For what we’re trying to do in the gameplay segments, we’re already making Ren’py scream in pain. Getting Ren’py to display animation the way it needs to be in the gameplay sections is a giant pain in the ass. The engine just wasn’t meant for it.
Unity on the other hand makes it much simpler, smoother and optimized. Furthermore, the actual gameplay code itself is far saner when done in Unity and the new engine just straight up gets rid of a lot of the screen language limitations that Ren’py shackled on.
As far as development difficulty: It’s a PowerPoint presentation with music, flags and buttons most of the time and a pretty simple TTRPG a bit of the time.
I don’t want to disparage any dev that’s had issues using Unity but I’m not rendering anything in Unity, just using it as the framework to hang my renders/animations/music/assets on. In that usage, Unity is quite simple and intuitive. Far more than Ren’py.