@dalias @Kierkegaanks @stux @Ttown @jmcs @mbrailer (going on a tangent) I don't know that asking those questions is silly, it's a matter of judgment, but what is the functional, organizational, motivational similarities/differences between monopoly/duopoly corporations and some Soviet Communist Bureau of Toothbrushes or whatever? Once you have concentrated power and an authoritarian structure you are going to end up with a lot of the same incentives and effects, except with non-state actors having even less transparency and accountability as democratic governments.
In this case VISA/MC have the power to regulate other companies that might only properly belong to a government, but is in private hands nonetheless. Moderation policies on large platforms which are open to the public but managed privately effectively become governance of peoples behavior, and can be compared with say a public Postal Service in how communication moderation polices are developed and applied.
Maybe you see that as an apples to volcanoes comparison but it's apples to oranges at worst and honeydew to grannysmith at best.
In an ideal world (not this one, lol, the one with spherical cows) at some level of effect governance/moderation decisions would inherit their legitimacy through a series of democratic process that have the population affected by the policy at its base. This level of process is too bureaucratic and heavyweight for small private groups, like your personal web forum or an independent store, but when more than, say, 1% of the population of a jurisdiction is subject to those policies then the case for governance oversight becomes stronger.