The issue is whether the thing is running a mainline compatible or distro kernel. If the device is running an orphan kernel, you’re screwed. This is the depreciation mechanism built into Android. It is “not Linux” because they are all orphans.
Technically even this is not enough if you want to get in the weeds. Technically the device can be on mainline but the company has a full time dev maintaining the required modules while the hardware itself it undocumented. If the hardware is documented at the api/registers level and it is already on mainline, it will likely remain supported for decades.
This is the true benchmark of ownership; public hardware documentation and fully merged support in the mainline kernel. Just for reference there is not a single mobile device that fully checks all of these boxes. Just to further illustrate how pervasive this is and how ignorant most of us are, the Raspberry π is proprietary with its full documentation locked under NDA. The vast majority of the silicon is made for a defunct TV tuner box, but you’ll never find documentation about any of this hardware at the registers level.
Your computer is the same, the microcode on ×86 is undocumented and things like the ALU architecture are not fully known except that it is a CISC wrapper around a RISC architecture. ARM is mostly proprietary at the registers level. All modems have been proprietary since the Atheros stuff over a decade back. The closest you can come to a FOSS computer are the old Duo series Intel chips supported by Libreboot and that is only because of the wonderful Leah Rowe’s hacking skills.
If you want to know what really works, go to linux-hardware.org and search. Either way, get the Hardware Probe from flathub or your package manager, run the test and review/upload your results to save the next person from similar issues. Seriously, don’t just ignore this. Upload your scan to the database with 233,034 other tested computers and 474,877 parts that have already been tested and uploaded. You can also see the configurations other people have used on the same hardware and get an idea if another kernel might work.