For a lot of series I feel exactly the opposite. You spend 5 minutes reading a chapter and then weeks or months waiting for the next one. The moment-to-moment pacing is often much better in anime adaptations.

The bigger problem is that a lot of manga/novel series run on forever so the anime adaptation has no chance of ever finishing the story. This doesn’t really have anything to do with the medium and is more about the way this stuff tends to get serialized in Japan incentivizing authors to never wrap their stories up.