Is it possible to allow sideloading and keep users safe?

> Are you allowed to run whatever computer program you want on the hardware you own?

Yes. It is a basic human right.

> This is a question where freedom, practicality, and reality all collide into a mess.

No; it isn't. The answer is clear and not messy. If you are not allowed to run programs of your choice, then it is not your hardware. Practicality and "reality" (whatever that means) are irrelevant issues here.

Maybe you prefer to use hardware that is not yours, but that is a different question.

Control over hardware isn’t actually the issue at stake here: many Android devices can unlock their bootloaders in a moderately safe way. Go nuts.

It’s a more tricky issue where Google and other parties can restrict access to their services to devices they deem legitimate. Their services, their rules. Your hardware. Different arguments required.

It’s everywhere: Widevine is used to prevent stealing 4K content (incl ATSC 3.0), gaming providers use it for anti-cheat, banks use it to rate limit abuse. It’s not just Android.

(I say this as someone with an Apple Vision Pro running visionOS 1.0 with the hope to jailbreak it one day. I’m actually unable to do whatever I want to their hardware, unlike my Pixel phones.)