Android 14 will warn you when trying to sideload updates for some Google apps
Android 14 introduces a number ofnew features for app stores, including an update ownership" API that lets an app store claim ownership over an app it installs. If any other app store tries to push an update to that app, Android will throw up a dialog asking you what they want to do. The dialog asks you if you want to update this app from [X]" since this app normally receives updates from [Y]" and warns that by updating from a different source, you may receive future updates from any source on your phone." You can choose to cancel or update anyway, which is good since it means one app store can't lock you out of getting app updates from somewhere else.
When taken in isolation, I think this dialog is a good addition to Android - I personally see no issues with informing users of the very valid risk that come with installing applications from outside the Play Store, especially ones coming from random websites (and not from APKMirror or F-droid or similar, more well-known sources). There are real risks associated with doing so, and it's a good idea to warn people of this in the highly unlikely event they both accidentally download a random APK and open it to install it.
However, the when' clause is doing a lot of heavy lifting here. Google has been slowly locking Android down for years now, and it's not unreasonable to assume that this is simply yet another stop along the way in that process. I don't think Google will ever fully remove sideloading from Android, but they sure will do whatever they can to make it as hard, cumbersome, annoying, and frustrating as possible.