As long as they don't maliciously comply, that would start a renaissance period, in my opinion. Suddenly, they'd be the good guys, instead of the worst offenders.
Everyone who wants to use the pure apple system can, everyone who wants to tinker can. Perfect world.
It is not perfect in the sense once the fence is off those who just want to be in walled garden and pay big money for it is not.
There is no perfect world for all. There could be a perfect world for each one. That is a difference. And yours may not be mine.
Just ask someone to compete with apple and get to the same level. Not killing one perfect world for many (most likely not really reader here it seemed) without creating a better tomorrow.
If you just think of tinker, before you know it china will take over say … or Russia … and we will have cheap but et-phone-home before you have a choice. Btw apple is dead. Cry your beloved apple then? No.
Ps. Just in case of doubt I hack my iphone and iPads if I can to do other things. It is my old device that is ignored … but not for all.
We already have this on Macbooks/Macs. macOS has SIP (System Integrity Protection) for example which you (Developers) can turn off to get full access. The average person does not even know this setting exists.
So the solution is quite simple.
I'm afraid Apple will frustrate the process though; Like, if you turn off "SIP" on iOS, they will disable Apple Pay, everything related to DRM videos (including Netflix, etc), DRM music (including Spotify, etc.), all App Store purchases, and so on.
Everyone who wants to use the pure apple system can, everyone who wants to tinker can. Perfect world.