You don't need a monopoly to have curated storefronts. For example, GOG is curated and if I don't like their curation, I can look at Steam or a plethora of other stores.
F-Droid has its own kind of curation, which I prefer to Google's curation; it gives me a decent guarantee that I'm looking at free software, and antifeatures are usually hilighted. However, I don't have to use F-Droid if I don't want to.
So maybe another entity can provide better curation that Google does. And maybe another entity can offer an uncurated store; if users prefer that, it's their choice.