Recent namechange here, but I've been posting on the CW forum for years. Submitting is really, really tough, and the lack of feedback is a killer, but it does help if you keep reminding yourself that it's a business. There's been a lot of criticism of agents on Twitter etc recently, a good deal of it around lack of responses/lack of feedback/lack of transparency, and while some of it is fair - the 'no response means no' thing that's crept in since 2020 is soul-destroying for writers, and makes the whole process even more difficult - some of the people being very vocal about agents have some seriously unrealistic expectations, which would involve the whole industry changing into something very different, which would immediately fail financially.
I've been through the submissions process twice - once with my first novel, and once with what will be my second published novel after deciding to leave my original agent, and I've talked to a lot of agents about the process. It's difficult to get your head around the numbers of submissions they receive - 400 in a week would be fairly standard - and, as a previous poster said, reading subs isn't the only, or even main, part of their job. You'd think it would be easy to tailor responses slightly, but even having a selection of form rejections to pick from would involve extra time per submission, and that adds up really quickly. The response times are already ridiculous, and anything that adds time is just going to stretch them out even further. There's also the fact that personalised feedback can open the agent up to the writer arguing the toss and sometimes getting nasty. I think the result of some of the recent anti-agent sentiment will be even more form rejections, so that they don't say anything that someone can latch onto and plaster all over Twitter.
Part of the problem is that writing a book is such a big undertaking that you don't start it unless you love writing and believe in your project. You pour your heart and soul into it, and then you send it out to people who reject it out of hand and never tell you why. But with most first novels, they're written alongside another job, or while being a SAHM or whatever your main life circumstances are. They're not paying the bills. But you then send it someone for whom this is their job. There's inevitably going to be a big gulf between the way authors feel about their project and the way agents view it, as one of thousands landing in their inbox.
Form rejections are so frustrating, because they can mean anything from 'This is the worst thing I've ever read. Your name is forever branded on my brain - and not in a remotely good way' to 'This looks pretty good, but it's not really my thing.' But personalised feedback in a rejection is so rare that you pretty much need to forget about getting it from agents. A few suggestions that may or may not help, as I'm in the process of writing a piece for my website on this topic - disregard if any of it is too basic:
Have you done enough editing? I usually do one big structural edit, another run through to fine-tune plot etc, a 'making it pretty' edit when I play around at a sentence level and start polishing up the theme etc, a copy edit/proofread type run through, and then a length edit as I tend to write long and have to come down. People are investing in their writing more than in the past, so some manuscripts are going to have been through a paid edit before going out on submission. You need to make sure yours is as polished and professional as possible.
Is your opening gripping? If you're looking at your submission and thinking 'I wish I had more than 50 pages as the really good bit is at page 63' or similar, you're probably starting in the wrong place. Agents are so busy that they're not going to hang on in there to see if it gets better.
Is your submission letter selling your work effectively? What I found very interesting was that when I was subbing as an already published writer, I got a lot of very fast responses - one in less than an hour - suggesting that agents keep an eye on their incoming emails and jump straight to anything that catches their attention. If your letter makes your project sound compelling, you might well jump the queue. Have a look at Juliet Mushen's website - there's an example of a really good query letter on there. I used an adapted version of it with good results. The format I used (minus the bit about my previous novel) was a very simple opening - 'I am seeking rep for my new novel, Title.' Then a paragraph saying what kind of novel it is, with a brief summary of the key points - this is the bit that needs to jump out - followed by 'I would position it along side [two comp titles]' and a single sentence about some the inspiration. Third paragraph gave a bit more detail about the plot - still very brief. Then a paragraph about me and my writing history, a quick mention of other projects in the pipeline, and then 'I attach the opening chapters and a synopsis and look forward to hearing from you.' Nothing fancy - factual and business-like.
Can you spot a form rejection? Writers sometimes latch onto the positives in a response, and take them as an indicator that they're on the right track, when they're actually part of a nice form rejection. Watch out for generic things like 'Although your submission was intriguing...' or 'I enjoyed reading your work...' or 'Although there is much to admire in your writing...' Personalised feedback will be very clearly...well, personalised.
Submit in fairly small batches. You don't want to send it to every agent on your list, only to realise when it's too late that there's something fixable letting your project down, because agents generally won't revisit something unless they've specifically invited you to revise and resubmit. Keep reviewing it. If you get 10 form rejections from 10 submissions, it might be worth pausing and seeing if you can get feedback on your submission package.
Re feedback - yes, it's hard to get quality feedback, but there are ways to do this without paying a lot of money for it. There are various facebook groups for beta readers, manuscript swaps etc. There are a couple of facebook groups that will critique your submission letter. I don't know how many writing forums are still going - I got my first ever feedback from a group on the old WriteWords forum, and it was invaluable. Try to find a local writing group, or start one of your own, either in-person or online. If you do have some money to spend, spend it wisely. Don't jump straight into an expensive edit or assessment before you've got some other feedback. In the early stages of writing/submitting, I personally think that any money is better spent on learning the craft rather than paying someone to polish your work. Look for courses/classes/workshops/mentoring etc. You just need some indication of where you are and where any weaknesses might be.
Read about psychic distance if you haven't already learned about this - it's a game changer in terms of writing quality!
I don't know if any of that is remotely useful - it's probably a long-winded way of saying that if you can remove the need for feedback from the submissions process, the whole thing becomes a bit less painful. Best of luck with it all - fingers crossed for a flood of full requests very soon!