I recently swapped out my AMD 3800X with a 5900X as an alternative to a full platform upgrade. I got it mostly for non-gaming workloads, however I do enjoy games.

Paired with my aging but still chugging 2080Ti, the max framerates in games I play did not significantly increase.

However I did get a significant improvement in 99-percentile framerate, and the games feel much smoother. YMMV, but it surprised me a bit.