Computer is always sort of open in that market segment. Apple ii, cpm and IBM PC. One can try (ps2) but all failed. Apple trying but still mac is sort of open and you can still run linux and windows on m1 sort of.

Phone ... smart phone opened? From Nokia, Newton, palmpilot, windows phone, ...

The question is whether the phone business model can bring it to desktop and conquer there. Wonder.

I like my phone is walled garden and I can take risk of my collections of pc.