Nobody has talked about supports always being underleveled for a while

A good support can generally do their job well while being underlevel and underfarmed. You're pretty much always going to be better off getting your carry as much xp and farm as possible.

I concur. I do find that finding ways to maximize my time in lane (less backs less deaths until the game opens up) keeps me even. After that just utilize those small downtime opportunities to be a cheerleader when someones mopping up a large minion wave.