Apple refurbs are better than they used to be. Fifteen years ago, I'd have said "do not buy Apple refurbs, it's good that they get a warranty because there's a 50% chance you'll be using the warranty as soon as you take it out of the box."
The refurb process seemed to be "Is it shiny? Does it turn on? Then ship it. If it's not shiny, then put it in a new case and if it turns on, ship it." Our customers who bought refurbs would be bringing them in for service as soon as they plugged them in. It wasn't uncommon that I'd be replacing half the parts in the machine.
They're better now, mostly because they aren't really refurbs any more, they're almost new customer returns; and occasionally you'll get a good deal on them, but they're usually priced pretty close to new. Back then Apple didn't really accept returns, so the refurbs were actual broken computers that were usually just sort of fixed.
So it really depends on what you want. If you actually want a refurbished computer, don't buy from Apple; you're not really keeping something good but a little bit older out of a landfill. If you want a slightly discounted virtually-new computer, that's what Apple is selling as refurbs.
I can't really suggest a particular third party refurbisher because I'd buy a broken one and fix it myself. I'm typing this on a 2018 MacBook Air that I got for really cheap because it was broken, I refurbed it. I'm not thrilled with it, it's too light, the keyboard sucks, so there's a decent chance this one will end up on ebay and I'll keep using my really well built 2012 MacBook Pros.