Obviously quality of gameplay matters, but point is that you need to take into account hours of gameplay, not just treat the game as a single unit, if you want to have a useful sense of what kind of value you're getting, since the amount of fun gameplay you get from a game isn't some sort of fixed quantity per game -- it colossally varies.

If the way one rates a game is to simply use the price of the game, and disregard how much you're going to play the thing, then what you incentivize developers to do is either (a) produce games coming out with enormous amounts of DLC, as Paradox does, if you don't count DLC price, (b) short games sold in "chapter" format, where someone buys multiple games to play what really amounts to one "game", (c) games with in-app purchases, data-harvesting or some form of way to generate an in-game revenue stream, or simply (d) short, small games.

I have a lot of games that I could grind for many hours

but I haven't done so, never will do so, because I've lost interest; they're no longer providing fun gameplay. I've gotten my hours out of the game, though that number is decoupled from the number of hours to complete the game. I have other games that I've played to completion a number of times, and some games

particularly roguelikes/roguelites

which aim for extreme replayability. The hours matter, but it's not the hours to complete the game that's relevant, but the hours I'm interested in playing the game and have fun with it.

For some genres, this doesn't vary all that much. Adventure games, I think, are a pretty good example of a genre where a player has to keep consuming new art and audio and writing and all that. They aren't usually all that replayable, though there are certainly adventure games that are significantly shorter or longer. But you won't be likely to find an adventure game that has ten, much less a hundred times as much reasonable gameplay as another adventure game.

But there are other genres, like roguelikes, where I don't really need new content from an artist to keep being thrown my way for the game to continue to provide fun gameplay. There, the hours of fun gameplay in a game can become absolutely enormous, vary by orders of magnitude across games in the genre and relative to games in other genres.