Google gives Android users a way to install unverified apps if they prove they really, really want to

The process is designed to create friction. Users must first enable developer mode in system settings. They then need to confirm that they're not being coerced. After that, they need to restart their phone and reauthenticate. And then they need to wait one day.

Thereafter, you can install apps from unverified developers on the device you notionally own. Users will have the option to enable such apps for seven days or indefinitely.

Next release 'indefinitely' will become 30 days and a year later there will be only 7 days.