Why always single elimination playoffs?

Seems like an unfair way of distributing prize money since a single elim bracket only gives you any confidence that the winner is the best team (at least they're undefeated). Anything after 1st really just depends on the seeding into the bracket which depends a lot on the RNG of which group the teams end up in.

Having watched a lot of fighting game tournaments (which are almost without exception double elim) I gotta say it's pretty hype when someone makes a deep run from loser's. Of course matches are a lot shorter but that argument doesn't work for say dota 2.

Wondering what people's thoughts are on this, it seems like pros just accept it, so maybe there's something I'm missing. Please no upfrag I don't want stars and it seems the downvotes on my old posts don't get rid of my progress.

Yeah, I think something like double-round robin as seen in round of 8 of APEX makes the most sense. Something like BEAT invitational seems a little drawn out imo. I'm not exactly sure why I feel this way though because it seems like it only ends up with 1 or 2 extra matches compared to APEX format in the end. Maybe because there are so many matches of the lost teams?
I feel like APEX format makes sure at least top two from each group gets to go to the semi, and Bo7 instead of Bo5 for Semi-final and Final minimizes the chances of luck playing a part in winning by favoring the team that took the closely contested maps. Also, longer matches for the favorites are more exciting to see.

#2 I think you mean double elim, but I agree that I like how APEX handles going from 8 to 4, it increased the chances that we get the best 4 teams in the semis to prevent a repeat of the APEX S1 finals. However, for tournaments with fewer teams where round robin decides seeding, or if you have fewer than 8 teams that qualify for playoffs I think there are a few reason why they would want to avoid it:

1. It adds a lot of games to the schedule and it time is an issue we could see situations like Contenders S0 where teams have to play for 10-12 hours in a day.

2. The finals is always an issue since you need to give an advantage to the team that made it there through the top bracket on top of having a lower bracket team that's played more games depending on where they dropped.

In the case of Contenders S1 I think that seeding played the role a double elim bracket would have, so I'm OK with the current format given that we have a high chance of getting 1vs2 Finals in both regions.

Edit: Added information.

Because most of the tournaments lately have been "seasons" and when is the last time you saw a sport with a season have double elim in it's playoffs?

These aren't simple round robin random seeded tournaments. You earn your seed in the playoffs by playing well.