Why do Smogon tournaments (official and unofficial) generally use a week to week schedule? Wouldn't things like the chatroom tours work better on average, esp. for certain formats?
Less ways to cheat, less time to scout, don't need to TO every day, and makes the spectator experience a lot easier. I've been lurking threads for different tournaments and it feels like 1/3rd matches are settled by activity, something that never happens when everyone is on board to play the entire tournament at a certain time, you only have to be available at one time block and you're good and as a TO there are way less moral decisions (especially subjective) you have to make.
For some tournaments, such as OU, there is an element of "How does the meta evolve each week?" but also tournaments such as Random Battles tournaments on forum I've seen also do this, and that has no prepping, or making a team, and basically no evolving format outside of the occasional changes to sets, or new Pokemon drops.
everyone else has basically answered, but yeah. to put it as simply as possible, not everyone can play at the exact same time and scheduling that with the size of some tours just absolutely is not feasible whatsoever