If Riot still isn't worried, they better begin to worry-

PUBG has dethroned Dota 2 based on highest concurrent user count on Steam.

Any moba games that loses popularity will have an effect on LoL - as the popularity of the genre as a whole is affected.

If Riot does not make drastic improvements soon, it will see a drastic decline.

The modern game is influenced by a handful of people (streamers) via word of mouth. Just as Riot had profit off the same word-of-mouth mechanics in its beginning days.