It depends on the category of device and what feature you want. I recently got an X1 Tablet (the 2-in-1 version of the X1 Carbon), and it barely works on Linux; there's a veritable zoo of inscrutable bugs that render the device very annoying to use (for example, Plasma's night mode disables when you re-attach the keyboard). It's clear that the FOSS ecosystem as a whole places little priority on touchscreeny things, either on the device end or the software end; the overlap between people hackish enough to fix weird bugs and people who find 2-in-1 tablets compelling enough to hack on is evidently smaller than with normal laptops.