I'll put my two cents in as someone who is a full grown adult:
My sister is only 5 years younger than me, and we're on completely different wavelengths. She was still in middle school when I was in high school, and she just started high school when I was already a sophmore in college. Even though we're both adults now, the generation gap is noticable. There are certain things that I know that she still has yet to know, all because of our modest age gap, and there are things she knows that I scratch my head at because people my age don't think that way. If I had to date someone with the same exact age gap right now, I couldn't do it, and I don't think they would be able to either. It could work out, but the fact that we're so generationally different would definitely make it difficult. That's not even getting into power imbalances and ease of manipulation.
So I said all that to say that it would probably be safe to say that dating someone just a single generation off would be difficult for everyone involved, so imagine two people that are two, or three, generations removed?