Wankels have only one advantage - they are about two times more powerful on same volume (you could consider them as very clean two stroke engines).

Unfortunately, Wankels have extremely huge mechanical problems - complex geometry (classic ICU are very close to just cylinders), need of better materials, depend on much better oil.

And also big problem is production scale, as I talked with people, they considered Wankels as toy, you will just utilize when it run out guarantee term.

For example, for standard ICU, considered big repair, sleeves, so they will continue working, sure, less heavy duty than new.