Well, the game being absolutely not made for any form of multiplayer, it's no surprise a tournament is clunky. Although to be fair, the video is extremely detailed and slow compared to what a tldr would last. Sure it would be nice to have an online "fleet builder" solution to participate, but that would cost several thousands of dollars to put in place so just a tad unrealistic for now.
As for the Discord requirement, sure I can understand how annoying it can be, but in the last tournaments that was also held on the forum there was huge issues of communication. When you have to postpone a planned stream because some of the submitted fleets are invalid and the participants don't reply for days, it tends to be pretty annoying too.