My understanding is that going to hybrid actually allowed Toyota to significantly simplify their transmissions relative to ICE vehicles, even without going full EV.
The planetary gear "eCVT" systems that Toyota and Ford use in many models are mechanically a lot simpler than a traditional automatic or sequential manual transmission. Few moving parts and no clutches at all. I don't know what the long term reliability of those drivetrains is is but I wouldn't be surprised if it's measurably measurably better than a traditional transmission + engine. There's a long educational video from Weber State University that gives a good walkthrough of what's going on in those things.
