I had an RX8. The rotary in it was nice. Powerful, small, but sucked for mileage and prone to leakage around the seals. The Wankel (that’s what it is at heart) needs improvement.
I had an issue with an air related component at one point, but no seal issues and got about 20-25mpg depending on how much of a “young man driving” I was being. I think I put over 200K on that sucker before selling it to my sister who put another 50K or so on it - never rebuilt, just maintained.
Don’t doubt it could be improved, but it’s there if needed.