In Silicon Valley you can go to Central Computer, though they aren't a tiny neighborhood shop by any means.
For laptops you might buy a Linux laptop.
I’m planning on using Central for a PC build in a month or so - definitely going to try to stretch my dollars.
Closest thing to that dream now is the framework laptop, which does have replaceable parts.
From other comments you can still sort of configure your own laptop.
What I was referring to was laptops already configured with Linux. So all the drivers are working, for example.
IDE is extremely slow, the connectors occupy a lot of precious space, and it hasn’t been used for modern drives for a very, very long time.
If anyone really needs IDE then they should get a USB IDE adapter for their use case.
Faulting motherboard manufacturers for removing ancient connectors is just grasping at straws.
But 2,5 kg versus 1,8 kg for a Lenovo with way better specs (I'm a traveller, weight is everything)... tough...
That's pretty much why phones never had a chance for this idea until very recently (and AFAIK, those recent examples are still not commercially available).
LG Gram laptop series. My LG Gram is the best laptop I ever had. It's lighter than Mac laptops.
Broadcom... that same hardware mfgr that makes your Debian install so much extra fun... (well, if you care about networking and integrated controllers...)
And back when PCs were far more open, good old IDE was always an option too.
Ever since BIOS became EFI, and flash ROMs started getting much bigger, it seems they've not been adding functionality but removing it slowly. The excuse is often "security" (against the user), and "legacy" (the oldest interfaces are also the most widely understood and stable).
That said, I'd stay away from the "prebuilt" manufacturers like Dell, Lenovo, HP, etc. if you want configurability. They've always had far less options in their BIOS than equivalent offerings from "enthusiast" or "gamer" oriented companies, although in the laptop space it's more difficult to do that.