This is the default iirc because that's what works for computer illiterate people. My partner specifically disabled that and does manual updates instead (I don't primarily use the Play store on my own device myself, so I don't have enough experience to judge whether this was user error). Despite that, their weather app got updated at some point after like five years of not updating it, and now everything (startup and detail screens) takes five times longer to load and it doesn't show the cities anymore that they want to see (can only show N on the screen and they iirc used to have 3 more or something). Of course there's no way to downgrade like you could on F-Droid (though, to be fair, it doesn't have releases going five years back, but it would also just never force this and it'd be safe to do updates intermittently because you can always choose "nah, don't like this change, I'll go back").

The closest experience I have is a GrapheneOS device where, after installing the Play Store, it ~daily tries to background install some VR app, no idea what that's about (purple hexagon logo, don't remember the name). I don't want this VR game on a work device. Installation fails because it requires manual confirmation (the store doesn't have background install permissions, which I think confuses the heck out of this google thing which is used to being a backdoor with superpowers) but the home screen keeps doing this animation to show another where this app is now loading, and fails some time later. For some reason it stopped prompting me with every attempt, not sure how I made it do that, but it switching home screens whenever I pick up the device is also annoying.

Background installs are totally a thing on the Play Store.