I believe this is already the case. You can purchase phones that may be bootloader unlocked, allowing custom firmware to be installed. This enables a tech-savvy user to sideload anything they like.
And we're back to "just break into the thing you've already paid for." Nope. Go away. No more smartphone crap.
Tech industry has completely lost the goddamn plot. Or more specifically, is doing everything it can to make it nigh impossible for the average user to navigate the info asymmetry to actually use the hardware they paid for.