Is Riot ignoring all these websites that boost, level up accounts, and sell them?
By selling accounts, These people are abusing a market that they have no rights to. They're outright stealing from Riot.
It needs to be taken care of in one way or another, and there's a high possibility that Riot can put these companies out of business and take whatever profits they were making. A lot of the market involves lazy players who want to make a smurf, but don't want to level it up to 30. Make it easy to level up to 30 and that's taken care of. Will there be more smurfs? Yes. Is that bad? No because matchmaking can pair smurfs with smurfs. Will that make Riot more money? Yes, because on all these new accounts, the players will buy champs with RP.
I'm not sure how to solve boosting, but I'm sure some of you have a good idea.