I use Stage Manger on both Mac and iPad. I really like it on the iPad and have not gone back to SplitView and Slide Over (even though I liked using that model just fine.) The experience differs greatly on the iPad from the Mac and for the better. If you use multiple displays on Mac, especially, Stage Manager can be frustrating. Stages are connected to a single display rather than across all displays. That said, my own view, is that Stage Manager is helpful, particularly when working on the MacBook Pro with no external display.
On the iPad implementation of Stage Manager, it’s much easier to move apps in and out of stages, get them to open in the stage that you are working on, move them out of stages, etc. If you have an iPad to try it; it’s worth checking out. Maybe you’ll still find it’s not your cup of tea, but I think you’ll see it’s a smoother experience than on the Mac.
I made a post some years ago about my thoughts on Stage Manager for iPadOS and my wish list.. Some of my review is dated because of the improvements to Stage Manager, but the wishlist part remains accurate. I also wrote about my thoughts on Stage Manager for macOS. No need to trudge through those posts; just putting them here for convenience.