I used to build custom apps for my Android all the time, install APKs, transfer files over USB, use USB tethering on my Linux computer, torrent, use a mouse and keyboard (I think iOS can do this now though), use the integrated terminal, etc.

A few years ago, iOS lacked basic features like widgets, NFC, calculator on their tablets, etc. And iOS still has a completely inferior keyboard (I used to write code and essays on my Android while walking) and a completely inferior notification system. Androids are also the only phones still offering a fingerprint scanner, which is way better for me. These nice things all combine well with the oppenness.

What's worse is that we're clearly in a progression of restriction. Bootloader restrictions, app installation restrictions, "age verification" requirements, etc. Openness is being locked down from every angle with serious momentum, it's not anticipated to stop here.