Is it possible to allow sideloading and keep users safe?

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.

The social structure of the smartphone app ecosystem is remarkably similar to the cable provider -> network -> show situation from before too.

They’re clearly just computers, they’re “hardware you own”, but you’ve never been able to run whatever software you want on them. But it’s been like this since the 1970’s and there’s never been an uproar over it.

For me the difference is that you know what you’re getting into when you buy a console, and it’s clear up front that it’s not for “general” computing. I’m inclined to put smart phones into this category as well, but I can see how reasonable people may disagree here.

I think there is a huge difference. You can perfectly live your life without a game console. Even if you are a game addict and it is absolutely necessary for you to live, you could buy a PC and game on that.

Smartphones are a necessity nowadays. Some banks only have smartphone apps (or require a smartphone app to log in to their website). Some insurers want you to upload invoices with an app. Some governments require an app to log in (e.g. the Dutch DigiID). You need a smartphone to communicate with a lot of organizations and groups.

Smartphones have become extremely essential. And two companies can decide what does and what doesn't get run on a smartphone and they can take their 30% over virtually everything. They can destroy a company by simply blocking their app on a whim (contrast with game studios, which could always publish their game for PC or Mac or whatever).

It is not a healthy, competitive market. It is the market version of a dictatorship. And Google forbidding non-app store installs is making it worse.

Governments should intervene to guarantee a healthy market (the EU is trying, but I think they are currently worried about the tariff wrath).