So nobody is really talking about it but... Runes??

They're stupidly expensive, and with the ever growing pool of champions it's sort of a giant wall for newer players. "I can get this flashy new champion who does all kinds of new stuff. Or I can buy a couple quints." Especially for a casual new player, they'll never be able to afford runes, let alone rune pages, as well as getting new champions to stop them from getting bored of playing the same ones over and over, or just the freeweek ones. Especially with how important runes are.