yeah, places that used to be a by-word for quality (yes, you, John Lewis) now seem to turn out a lot of crap. And, last time I was in there, rather dull crap too. But at least they did refund me for the desk that just started listing and leaning!
I don't know what your style is, OP, but there's a company called Unto This Last which makes good furniture. It's certified sustainable birch ply and comes in a variety of finishes. It's customisable to a degree in terms of sizes and finishes, they manufacture to order and you can get items relaminated/recovered in Lino by them We've got tables and chairs made by them which have lasted very well for nearly 2 decades now. Can't vouch for the wardrobes/cabinets.
String and Vitso are good, modular shelving and drawer units.
We've had wardrobes and bookshelves custom built. Spendy but they're there forever. Fine for us in this house, because we'll get at least 20 years use out of them. A good cabinet maker might be worth hiring?
Ercol is good - I've inherited some from my mum, but I think the same styles are still made. I am a bit suspicious of a lot of 'vintage' furnture - too often I've checked the back of desks and the like and they've been patched up with chipboard. But I'm sure there are great things out there, it's just I don't know how to track them down and verify them. So I'd rather buy new.
We're looking to buy a sofa or two over the next year and I find the websites are pretty uninformative about what is actually inside the sofa - hardwood frame, proper spring coils, foam rather than feather cushions, etc. I don't want to spend more than £2.5k and, for that, I want something really good. We'll see!