Why is riot not changing the Meta?

I mean its obvious that League of Legends lost active players. I know very much people who dont play League anymore because of the Meta etc. I mean, this meta is boring af every tank just runs over u and u r dead. When there where the Assassin Meta there where lots of skillmatchups with outplaypotentional etc. In the active Meta are just Tanks running all down. And even if I see what Riot wanna change in MId.Season (AP-Items) i get cancer