There really needs to be an option to include Linux or even just no OS. It's really frustrating to have to pay the Microsoft tax for something that's supposed to give me a choice and modularity.
If I'm being honest, there's very little chance of me leaving my M1 MBA for anything other than another Apple Silicon machine any time soon. That being said, a modular laptop that was also fully open would be very tempting, particularly if it were otherwise competitive (in terms of portability, performance, battery life, display quality, etc.).
All of that would probably also require supporting next-gen desktop ARM SOCs (like the 8cx, but from the future), or waiting for x86 to catch up and then copying Purism in neutralizing Intel ME / AMD PSP.