I've been having a great time with my HP Elitebook 845 G9 which I got on sale for $950. It's crazy expensive now due to inflation but you might be able to snag it on sale somewhere. Mine came with an AMD Ryzen 6800U with 32GB of RAM and I manually replaced the SSD with a cheap 1TB one I found on Amazon. There's a FreeDOS option that allows you save $200 bucks by not buying a Windows license.

I find that the key components to check for Linux compatibility are the Wifi, webcam, and sound modules. For wifi, anything with an Intel or Atheros chip is usually supported very well

If you want to buy new (or can find one used): framework, no contest

Used, just see what's available around you on offerup/craigslist/fb market/etc then google that laptop and linux, or see if you can find an archwiki page for that model. This is what i did a while ago, i found a used thinkpad t14s for a good price, checked the archwiki page for it ( https://wiki.archlinux.org/title/Lenovo_Thinkpad_T14s_(AMD)_Gen_1 ) and everything i cared about was marked as working, and it's worked well for me

What's the budget? I got myself a Tuxedo Pulse Gen2 this year and am very happy with it, I have no complains at all regarding built-quality, performance and Linux-compatibility. (However, it appears they don't offer many Ryzen-notebooks anymore, I just looked and only found one model :-()

Thinkpads are popular and well respected among linux users, and the trackpoint is dope as well. If you want a gpu workstation that also works for gaming, check out the P series.

You seem to be German, so your solution is a Tuxedo laptop or computer. A German Linux hardware company.