My personal security metric is "how many bitcoins would I leave in a wallet app on this phone".
Currently that number is about 1 ($30k) on an up to date android. I believe that if I had more bitcoins on a phone, and told people about it, there's a good chance a targeted exploit would steal those keys. Even if I had them encrypted, at some point I have to type a password in to decrypt, and that would be the point they'd be stolen.
However, on an iOS device (which is more robustly locked down), I'd probably happily store 10 bitcoins. (if I had them, hah!)
On dedicated hardware (like a trezor wallet), i'd also be confident up to about 10 bitcoins (far less attack surface, but also a less competent security team than Apple can afford).
On an outdated android, it would be more like 0.1 bitcoins - there are trivial ways to root them from the web browser and any old website can do it!
Considering that for many people, access to all the private data on their phone could ruin their job, relationships, and even put them in prison, I'm sure a lot of people value the security of their phone at multiple years salary. If I have to choose between that and the ability to run an emulated game slightly faster, I'm totally choosing security!