The devices are locked down, sure, but there are strong incentives to upstream code and fund further development upstream. Linux ”won” because of this. You can’t build and develop Linux for such a wide audience and hardware flora with a bunch of hobbyists.

if these companies were upstreaming code, it would not be a problem to replace the factory operating system on their products with something else. however just like phone makers, they don’t upstream the driver code needed for the onboard devices to work.

so far the only good I found to have come of it, is that after we find a vulnerability in their code, we can open a shell in the system and use ready made familiar tools to try to tame the devices from inside. until they force an update that patches the vuln because it got too popular, and you are locked out again.