Hot take: 26 year olds should not fuck 19 year olds.
It's not illegal, but it's still weird, creepy and potentially harmful and no amount of lambasting about "the problematic age gap discourse" will make it not true.
OP, what's it like being clinically allergic to context? Every other question you pose basically boils down to historically particular context, this one especially.
Whenever anybody says it's not 'weird, creepy, and potentially harmful' you say 'power dynamics' but power dynamics are about the context of the relationship when straight up legality is not involved.