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.

It seems that this is another one of those things where the lowest common denominator sets the rules for everyone. Most people arent tech savvy programmers so giving them the freedom to do 'whatever they want' will lead them to hurt themselves in some way. Of course this is not an excuse for locking down your hardware. Smartphones just came into being as a consumer-first product and didnt require many of the freedoms that programmers needed, which is why computers are fundamentally more open than smartphones. Apple of course is trying to change that with their Macs

> this is another one of those things where the lowest common denominator sets the rules for everyone

In that case, the solution should be to raise the lowest commmon denominator. Lots of issues like that could be prevented by investing in education to increase technology literacy. But long term investments (even public ones) do not match well with quarterly reports.

I would say young people grow up with tech and usually are very tech literate.