I don't think it's really about the movies. He always knew his success was temporary and just pumped out movies while he was still getting high paying roles. A lot of them were very entertaining, but everyone knew there was limits to how long that formula could keep going.

His public persona suffered quite a hit after the whole DCU thing I think. He really wanted to be Black Adam, but that character starts off as a villain. That was an issue, because Dwayne Johnson always has "I don't lose any fights" in his contracts. So obviously he can't be a movie villain, because the villain isn't supposed to win. So they skipped straight to where he is a hero, without the build-up, and everyone learned that his contracts require him to never lose a fight, which makes him come off as an ass, unlike his public profile prior to that.

Then he stages some kind of DCU coup which I'm not sure how he has the chops to do, and spends a lot of political capital on getting Henry Cavill back as Superman, but immediately after the whole DCU leadership is upended and all of that is scrapped. I don't know how that affected his industry connections, but I doubt it was in a positive way.

TL;DR: Everyone knew Dwayne Johnson wouldn't last, including himself, which is why so many movies with him were pumped out while he was still on top. Then he lost some popularity among fans and execs due to some DCU stuff.