Both are very bad. CP2077 because of all the continuous errors and bugs, even today. WD Legion because they chose to get rid of a main character and unhinges story. Both aren't mediocre.

Raking in money doesn't make it a good game.

I'd value Valhalla as mediocre. It's pretty, does a lot of things good, but it's repetitive and the gameplay has nothing to do with Assassin's Creed. It's not bad, but has very little going for it.

There are still plenty of mediocre games. I'm actually playing one right now, for testing purposes. It isn't very good, but you can't really fault it either.

Edit: It's also with movies and series. I just watched resident Evil (2022) and pretty much enjoyed it. Not stellar, but definitely entertaining. The reviews were all 5/5 or 1/5, no middle ground. I guess that's just public opinion. You don't get attention if you 'just like it somewhat'...