Is it possible to allow sideloading and keep users safe?

"sideloading" connotates something that is negative.

On systems before apple's locked-down iphone, it was just called "installing".

The PC revolution started with people just inserting their software into the comptuer and running it. You didn't have to ask the computer manufacturer or the OS vendor permission to do it.

And note that apple doesn't allow you to protect yourself. You cannot install a firewall and block arbitrary software on your phone. For example, you can not block apple telemetry.

If you consider developer has the right to determine who runs their software, it is actually.

My last 10 apk installs:

- 9 apps not available in the local store - 1 app I changed some setting in the manifest

For less technical people it will also include some shady apk's for example promising free La Liga match broadcast but then scraping everything from phone.