The problem is that they aren't being told "we won't let people buy this through us", they're told "this needs to go entirely or no more credit cards for you".
The problem isn't just "the Payment Processor doesn't want to support this game" but also "this game shows Guilt-By-Association that your platform's money might go to 'criminals' or 'sinners'."
Guilt-By-Association is real gross, but a large part of the current fight, too, especially looking at itch.io's payment processor-required actions, not just Steam's.
That don't use Visa/Mastercard? The bans aren't coming from the platforms but from the payment processors.
All of those are still prone to censorship if the attacking group is motivated enough. Even crypto, which should be the ideal solution to this problem, is not ideal because most transactions are performed through centralized exchanges which can easily blacklist whatever transactions they want.
You can't even realistically have a F2P game that requires a high spec machine because of how the market works.