It's not though, in the current system everything must go through those shitty companies, so they can dictate anything, and if Steam disobeys they essentially block them from receiving money, and it's impossible to jump ships because creating a competition is essentially impossible, no one will be able to handle the Volume of Valve's transactions and it needs to be all done by one entity. Ñ
In the system I'm describing once you're in the crypto space no one can dictate anything. The same people could try to act as gatekeepers, but it's almost impossible because anyone with Ethereum can sell them to you, so if an exchange threatens to not buy Ethereum from Valve they can simply go to any other exchange, hell, they themselves could sell Ethereum to users who would then use the Ethereum to buy games returning the Ethereum to Valve to be sold again, and if not anyone with enough capital can start an exchange selling Ethereum to users and buying it from Valve, even with small initial capital you would likely grow very quickly doing this. And the best part is that Valve can sell their Ethereum to different exchanges in any ratio they want to, so it's essentially impossible for one of them to dictate anything because 1 big exchange can be replaced by 10 smaller ones in a heartbeat without any disruption to the system.
Steam remembers my card, so I don't have to input it there everytime. I get that you wouldn't want to put your card info somewhere shady, but Steam is not that. Also, most banks nowadays have virtual cards you can use for that sort of thing, some even have one use cards that self destroy after a single purchase. So the safety that PayPal used to offer is not that important anymore.