The onus is on you to prove that it’s rigged.
Also, e-sports does NOT have randomly generated teams at all. Teams scout and sign players, and if the players can’t perform, they’re out of a job.
Everything Blizzard ever said about Competitive and its matchmaking is compiled here:
The rating and matchmaking system is confusing, and a good overview does not appear to be available. The official overview (1, 48) is incomplete and does not answer a number of common player questions and concerns. This information below is gathered from sporadic blue posts and developer update videos, and salted with my own experience and experiments, various forum threads, and watching streams. Note that since Blizzard does not give exact algorithms, I do have to fill in some gaps, or leave so…
People ignore it though, or flat-out say that the dev team is lying, because they want to believe that matchmaking is rigged.