developers will stop disclosing it. There’s no benefit to doing so.

That would be against the rules of the platform. They risk to get banned or the game being removed from the store.

Says the person who wants to be told when they're "playing slop" because if no one tells them, they can't tell. Yet demands they be told.

I think, for people like you, they should just have a random number generator - 0 Steam say it's not slop, 1 they say it's slop. It would make you happy, yes? Since you're basing your entire decision on something you can't actually discern.