@Sheindebt I think a good part of it is mental (and physical) maturity and agency imbalance.
If it was a 13 yr old and a 20 it’s pretty bad - but an 18yr old and a 25? Or a 33 and a 40?
The older person in a youth relationship has much more power and experience behind them making the relationship inherently unequal. We do so much critical growth in such a small period of time and during that period it’s best not to have that imbalance shape you.