Just buy a Thinkpad or another laptop that has good support for Linux.
I definitely get the argument that your supporting Linux by buying a System 76 computer, but the last time I checked IBM Red Hat isn't exactly a charity.
I know there are a bunch of laptops that have good support for Linux, but I'm talking one more level deep than that. Good support for Coreboot UEFI is hard to come by, and FOSS EC firmware (this makes laptop specific features possible) to my knowledge is unique to System76.
Those two components are the unique selling propositions System76 has over your standard Linux-ready laptop. And they aren't quite unique when you realize System76 is commissioning laptops from the likes of Clevo.
E: I know I just rehashed by last comment a little bit, but it felt like the point didn't come across properly. I was supporting the mention that the Linux-first USP of S76 wasn't strong enough, and building on top of it.
Something to do with free software everything, not features that Coreboot provides that a standard InsydeH2O UEFI BIOS doesn't have. I don't quite get it myself, and it is quite a niche, but some people care more about it more than others. A very small amount of people.
There's great risk installing such a thing yourself, as you can end up bricking your laptop with very little recourse than to break out a soldering iron. Or if you don't do your homework carefully, end up with a half functioning PC because things like display brightness and audio apparently require driver binaries within UEFI that need to be there to work.
That is a Clevo laptop, but many vendors do use their models and don't advertise as such. Gigabyte, for example, uses Clevo for their bottom tier models with no special marketing name. I don't doubt that their other models are Clevo, but I can tell that those ones are.
Just buy a Thinkpad or another laptop that has good support for Linux.
I definitely get the argument that your supporting Linux by buying a System 76 computer, but the last time I checked IBM Red Hat isn't exactly a charity.