I’ve heard of some blockchain based systems referred to as decentralized cloud before (including stuff like Sia and Storj, which I guess is what OP wants). I haven’t looked into them that much, but IIUC they push most (all?) controls and so on to the edge. I’m not sure I’d use them though since the networks aren’t super large.

• The location functionality has significantly improved recently since it no longer relies solely on GPS, but yeah, it could still be improved.
• Generally, I’ve found the apps that tend to have problems with exploit protection are games, VPNs, and banking apps (which is probably the sort of app you’d most want exploit protection on…). I’m not sure if I’ve ever had an actual problem with other apps honestly.
• While NFC works, Google Pay does not. Google needs to basically certify the OS for it to work, and they refuse to do so (monopoly gonna monopoly). Basically, this means if you’re in the US or some other country where Google Pay is pretty much the only payment option on Android, NFC payments don’t work. Some places in Europe at least have NFC payments available through banking apps though, so if you happen to reside in one of those countries and your bank has one of those apps with payment support, you should be fine.