I'm looking to expand our offering to better support esports leagues and tournaments. Esports fans: who are the incumbents? Are there any particular sites where leagues/tournaments are always hosted? I know of a couple but just want to see if I'm missing any.
By host do you mean what platforms are they streamed on or do you mean where are they organized/where can you view the brackets and participants etc?
The latter. Where you can view brackets, participants, stats, teams, etc.
There have been and still are many, but I've noticed lately that almost all tournaments I see use smash.gg. (Honorable mention to boom.tv)