Law, not technology, is the true battlefield in the War on General Purpose Computing, a subject I've been raising the alarm about for decades now:
https://memex.craphound.com/2012/01/10/lockdown-the-coming-war-on-general-purpose-computing/
The fact that there's no technical way to enforce these restrictions means that the companies that benefit from them have to pitch their arguments to lawmakers, not customers. If you have something that works, you use it in your sales pitch, like Signal, whose actual, working security is a big part of its appeal to users.
If you have something that doesn't work, you use it in your lobbying pitch, like Apple, who justify their 30% ripoff app tax – which they can only charge because it's a felony to reverse-engineer your iPhone so you can use a different app store – by telling lawmakers that locking down their platform is essential to the security and privacy of iPhone owners:
https://pluralistic.net/2024/01/12/youre-holding-it-wrong/#if-dishwashers-were-iphones
Google lost a brutal antitrust case brought by Epic Games, makers of Fortnite:
https://pluralistic.net/2023/12/12/im-feeling-lucky/#hugger-mugger
Epic's suit contended that Google had violated antitrust law by creating exclusivity deals with carriers and device makers that locked Android users into Google's app store, which meant that Epic had to surrender 30% of its mobile earnings to Google.
Google lost that case – badly. It turns out that judges don't like it when you deliberately destroy evidence:
They say that when you find yourself in a hole, you should stop digging, but Google can't put down the shovel. After the court ordered Google to open up its app store, the company just ignored the order, which is a thing that judges hate even more than destroying evidence:
https://www.justice.gov/atr/case/epic-games-inc-v-google-llc
So it was that last month, Google found itself with just two weeks to comply with the open app store order, or else:
https://www.theverge.com/news/717440/google-epic-open-play-store-emergency-stay
Google was ordered to make it possible to install new app stores as apps, so you could go into Google Play, search for a different app store, and, with a single click, install it on your phone, and switch to getting your apps from that store, rather than Google's.
That's what's behind Google's new ban on "sideloading": this is a form of malicious compliance with the court orders stemming from its losses to Epic Games. In fact, it's not even malicious compliance – it's malicious noncompliance