The thing is there is no "sports" industry just like there is no esports industry. Most sports hardly any money at all. Many sports simply cannot be played at even a semiprofessional level.

League of Legends was big so they were able to create a professional league at the height of the streaming explosion. Now viewers have mostly pivoted to watching reality content on Twitch because for some reason that is what most people want. Sustaining interest in a game is hard enough already but trying to sustain interest in a professional league based on a game that is nearly 15 years old is a monumental task. League is probably the most broadcastable competitive team video game just because it lends itself to seeing all the action from a bird's eye view by default. Other games are extremely hard to follow unless you already play which limits your potential audience massively. By contrast every popular professional sport can be enjoyed casually to some extent and you even get a geographical region team that matches where you live to root for by default.

Everything is stacked against the success of Esports being big business on its own. Getting cult of personality streamers involved helps a lot. Hikaru or Levy Rozman being in a chess tournament for example. Pros in most games don't have the time or inclination to build a massive stream audience while grinding for 10+ hours a day to stay on top.