Valve pays 0 dollars for publishers to be exclusive to Steam.

Being on Steam has always been a benefit to publishers. Even in 2004, people wanted on the platform because it's the platform that Half-Life 2 launched. That is a built-in install base that will have advertising right in their face about your game. Valve pays 0 dollars because Valve doesn't have to pay money, they already have other ways of paying.

I never said any of them are any better, just because it’s industry standard doesn’t make it good. If you pay publishers to release games exclusively on your platform and you are not actively funding development you are anti-competitive in my eyes. (Also Stadia doesn’t exist anymore)

EA partnered with Valve to bring EA games to Steam. (https://www.techspot.com/news/82538-ea-confirms-rumors-partnership-valve-bring-games-back.html) This was a direct agreement made with Steam. Not only has money changed hands but Valve has adjusted their revenue rates to get people to release on their platform because of this. Steam has built-in exclusivity clauses. You can release on other platforms but you can't price your game differently on other platforms. Additionally, if you have a store page on Steam, you must release it on Steam at the same time or sooner than everyone else. Valve does anti-competitive stuff like this all of the time. People just make excuses or accept it but this is Valve driving away competition.

Most of the time they try to snatch up games that are already finished or were already planning to release on Steam/GOG. Sometimes they even pull games from other stores (Rocket League and Fall Guys) after they released or just before they release (Metro). That’s not the practices of someone who wants to compete but someone who wants to get into the market by force without actively doing anything good for the industry.

You should look up where most of the Valve games come from. Counter-Strike, Dota 2, L4D, Portal, Team Fortress, etc were all game studios bought up and told they'd only get to make games for Valve. Remember In the Valley of Gods? https://en.wikipedia.org/wiki/Campo_Santo_(company) Valve bought the team under the promise they'd continue making a game and just put the dev team on Half-Life: Alyx. I'd say Valve is almost worse because they don't make publishing deals, they'll buy and adsorb you into their collective.