I have been modding my Android phones for years and at a certain point I realised that it is not sustainable. Most OEMs do not provide proper updates and end up making the performance worse with subsequent releases as they are focused on that year's flagship. Open-source ROMs end up using blobs from other Android versions released by the manufacturer and they eventually cause lots of issues with camera and wireless performance, not to say a buggy nightly release from someone can start having adverse effects like battery drain.But how can they. Everyone is going to use their devices for some common tasks and some tasks uniquely random to that user. I remember having to sell off my iPad within 3 days of buying it because it couldn't do the simple task of playing a file over network, even after spending 1000 bucks on software. Apparently the way Apple had implemented it, and hence all third party apps had to do it too, was to have a server app running on the hardware from which one was supposed to stream the data from. I think I had created a thread for this exact issue on TE back in the day.
Also, for me personally, ownership of the hardware and freedom to do with it what I want feels quite important. I guess it stems from the fact that I was always tinkering with Android phones and never running the stock firmware, as most of us on this forum would. I really had fun with the last iPhone I had - 4s,just because of the jailbreak. I remember using Gesture based navigation thanks to Zephyr nearly a decade ago. This is the power of open systems and something which I, personally, wouldn't like to give up.
You can never truly own your device. It is about the extent of illusion of freedom that you get and how much that matters to you. Eventually I turned to iOS because it just works. Most of the jailbreaking tweaks eventually made it to iOS as did Android features. Both platforms are pretty mature now but iOS with its ecosystem and optimisation simply provides a much better daily experience, especially as I care a lot about my privacy.
Having said so, I dumped Samsung's OneUI on my tab after a couple of months and switched to Lineage, simply because it is faster and I don't care about the camera or wireless performance on it as I mainly use it for reading and watching stuff. I simply don't think I would switch to an Android phone though as I have moved past mobile gaming and need the phone to do everything else really well.