Sure, the lockdown situation is worse than things are currently. You're likely to need per-device hacks that unlock it and enable freedom for users.
Even in that scenario though, ARM devices use standards too. There's a reason I can generally pick up any Android device and know what needs to be done to build my own OS for it. We just lack tooling that makes that incredibly easy and lack maintainers who want to make those devices work with the mainstream linux kernel.
Having open devices though (outside of Apple) is still my bet. We still need to make that process smoother but that just means there's lots of low hanging fruit :)
Still I don't see this scaling unless more of the ARM stuff is standardized or upstreamed by manufacturers - IMHO there is simply not enough OSS developers being both willing and able to do the often menial yet necessary platform adaptation work.
For that reason I'm morehopeful about built-to-be-open hardware like the Pine Phone, as that could help reducing or removing the device support treadmill, so useful features can be actually developed. :)
Even in that scenario though, ARM devices use standards too. There's a reason I can generally pick up any Android device and know what needs to be done to build my own OS for it. We just lack tooling that makes that incredibly easy and lack maintainers who want to make those devices work with the mainstream linux kernel.
Having open devices though (outside of Apple) is still my bet. We still need to make that process smoother but that just means there's lots of low hanging fruit :)