Fighting games are supposed to be the ultimate 1v1 psychological sport. But the scene still allows mid set coaching just to manufacture storylines for the broadcast.
Look at the standard for chess. Chess is universally respected as a pure mental competition, and the rules explicitly ban live coaching during competitive games. For online play, getting help from anyone during a match is a severe fair play violation that results in an account ban. For offline over the board play, federations strictly forbid coaches from communicating with players during games. You can do pre game and post game analysis all you want, but during the actual match, all decisions must be your own.
The FGC sacrifices the purity of 1v1 adaptation just to orchestrate a moment on stream and give commentators something to talk about. Mid match coaching undermines the entire concept of the mind game. No outside interference should be allowed during an active tournament set. If you cannot adapt on your own in real time, you deserve to lose.
There is a massive difference between a crowd watching a match and a posse of bracket cheerleaders standing directly behind a setup screaming instructions. If you need three friends acting as a hive mind to tell you when to tech a throw or what the frame data is, you are not actually competing 1v1. The scene calls it hype, but it is just a crutch for players who cannot process the mental stack on their own.
The chess fair play rules and more in the replies.