Security by default is fine, but not if its being forced.
If I go out of my way to root my phone or sideload an app, I have a reason for that. I’m fine with an app going “Hey! This phone is rooted / this app is not from an official source! Wait 10s before you can click ‘I understand and take full responsibikity in case of a security breach’”.
I’m not OK with an app going “I will not work on this device because yiur environment is non-standard, period”.