Earlier quoted context omitted.
I think you might not be considering personal bugfixes (X interaction is great for the common denominator, annoying to me), long-term support (I want to use my device securely in 2045), or custom features (I want to be able to do X, but only 0.001% of people care so Apple doesn't). I use Android, so I can't be more specific. I have heard the unverified complaint that Apple sometimes slows down old devices as new ones…
I don't really understand this. You plan to single handedly replace the entire OS and security teams to maintain the OS on your phone for a decade? How will you update the kernel when the proprietary driver blobs stop being maintained?
Yes, it would be very hard. But today it is impossible, so very hard is hardly a complaint you can make in comparison.
Did my other two examples seem more reasonable?