You don't have to side load anything. If you think it's worth paying 30% for the Apple review process etc. You're free to do so. Just let others make their own decisions.

To side-load an app on an iPhone you need to sign it with a developer certificate (and apple will actually do it for you). You can only run the app if you trust said certificate (you will get a prompt saying something like going in the settings, tapping on the developer name and then tapping "Trust". You would then need to confirm using your passcode/faceid/touchid). It's not like anyone can put apps on your phone and being able to launch them without any friction.

Side loading on Android does not require a certificate. What people are suggesting is allowing side loading something like fortnite to by-pass the App Store, like what is possible on Android.

Side loading is not the same as installing apps as a developer for testing.

2nd, sure you need a passcode etc to accept the install, this every-now-n-then gets by passed.

Don't side load then.

What happens if you get picked up by the police, and your stuff is confiscated, and you get it back, how do you trust your apps on your phone if side-loading is allowed?

You can't. You can't know if whatsapp was replaced with whatsapp that syphon your data.

"Don't side load then." is a poor argument.

If the police has had your phone it is compromised. End of story. Throw it in the river...

Or recycle it. Don’t pollute the rivers!

How would they side load apps if the phone is locked?

What if they can bypass a locked phone?

Then side loading is the least of your problems.

Make sure it's still signed by Facebook. Whatever good that will do for your privacy. Next question.