it's rather ironic to complain that hiring managers are discriminating by age when they don't like seeing a DoB when the precise reason they don't want to see it is to avoid discrimination by age.
Yeah, the irony was kind of the point I was making. 
WRT to touting your CV round potential employers in person - I’m reminded of a funny story, just to lighten the mood a bit here!
20+ years ago, I was working in a large branch of a major retail chain, let's call them Cool & Co, who were widely viewed as a fairly benevolent employer and consequently very popular with job hunters at that time. We used to get anything up to half a dozen people a week coming into the shop to drop off CVs, and even more arriving by post, all on spec. The company weren't explicitly opposed to this (I got my own job there by posting them a speculative CV) but sometimes the volume of it was just overwhelming, and they only tended to hire at certain times of the year, whereas the barrage of CVs was relentless.
Eventually our manager (who was a bit of a grumpy bastard tbh) said he just wouldn't accept any more, and if anyone came in with a CV we were to politely but firmly tell them there were no vacancies and we were sorry but we couldn't pass on their CV.
One day a woman came in with hers and tried to give it to me, so I gave her this spiel but she wouldn't take no for an answer. She'd just moved to this country and maybe the culture where she was from is different, idk, but she was very pushy and kept telling me how much she wanted to work there, how great she'd be at the job etc etc. I kept repeating I was sorry but there were no vacancies.
Clearly she didn't believe me and asked to speak to the manager. Knowing he'd be furious, I said no, he never spoke directly with people who dropped off CVs, again I was sorry etc. Again she persisted, and on and on it went. Eventually, in despair because she wouldn't leave, I called down to him and grovellingly asked him to come up and talk to her, which he did - essentially telling her the same as I'd told her, after which she finally went away. I on the other hand got a telling off because presumably I was supposed to have frogmarched her out of the store or something!
Fast forward to the next morning, and I get paged in work that there's a phone call for me, by name. On the line is a woman whom I immediately recognised, by her very distinctive accent, as being my persistent job hunter from the day before - but I knew I'd never told her my name, nor had she heard me call the manager, so she couldn't have learned it that way. She launches into her spiel again about how desperate she is to work for the company, blah blah, clearly with no idea that she's speaking to the same person as the day before.
Me (very confused and annoyed by this stage): Excuse me, sorry, but how did you get my name?
Her: Oh, I've just moved in as a lodger with F [a friend of mine] and I was telling her that I really wanted to work for Cool & Co, so she mentioned that she had a friend who worked there and that maybe if I gave you a call, you could give me some pointers on how to get a job there or something.
Me: Oh really?
Her: Yeah, the thing is you see, I went in there yesterday and the woman I spoke to was really unhelpful and just tried to fob me off. She kept saying there were no jobs but I know that's just what they SAY, so I was hoping that if I had a contact, like you, you could maybe put in a word for me?
Me (with some relish): Actually, the person you spoke to yesterday was ME, and I’m sorry to tell you that there really ARE no jobs! Now please don't call me again! 
So, I don't do THAT at least. 🤷♀️