Android has always been open, for a given value of "open," a property that companies like Samsung, Amazon, and Epic have used to create their own alternatives to the Play Store. But actually using those alternatives has always been a bit of a headache, with Android itself treating each individual app downloaded as a side-loaded app. Starting with Android 12, using alternative app stores will be a little more seamless, at least some of the time.
To put it simply: if an alternate app store fulfills four safety requirements on Android 12, the system will let it skip the warning pop-up that appears before any side-loaded app update. The requirements are 1) the app store needs to be properly flagged to skip this step, 2) the app has to be formatted for Android 10 or later, 3) the app store installed the app previously (or it's an update to the app store itself), and 4) the app store declares the correct permission.
Okay, maybe not so simple. But it's possible.
With all those ducks in a row, users should be able to skip the pop-up warning screens that frequent non-Play Store stores, at least on app updates. They'll probably still have to manually approve whenever a new app is installed for the first time, as seen in the Amazon Appstore screenshot above. If this is all that there is to Google's previous promises of better operation with alternative app stores, it isn't a whole heck of a lot.
Google might revisit this, especially since Android 12's smoother operation with third-party app stores seems to be almost entirely a reaction to current anti-trust rumblings in the US and elsewhere. It isn't as if Google is delivering exactly what Epic asked for in its highly public
pissing contest lawsuit over Fortnite in-app purchase revenues. ("What Epic asked for" is more or less to keep all the money made, even if Google's proprietary platform is an essential part of it.) But as written, this kind of highly conditional bow to third-party app stores is unlikely to sway any regulators that are eager to catch Google stepping over the line of monopolistic practices.