Riot, have you ever considered selling level 25/30 accounts?
I know doing this is buying power, but it also destroys the market for level 30 smurfs (reducing the number of bot levelers in low level games) and allows people who want to bypass the long pre-30 grind to do so.
Idk, people probably won't like this because it's "buying power" but League has always been pay to win before level 30 anyways.