Payment processors have major network effects in that infra setup is expensive, banks need to be onboarded one-by-one, and whichever network has the most consumers, businesses will gravitate towards it. Iterate this over 20 years, and this always results in natural monopolies / duopolies. This creates a natural chokepoint/linchpin over which millions of people's mutually exclusive needs are getting banged at; including consumers at large, govs at large, and special-interest groups at large.

Absent crystal clear legislation -and porn is anything, but- this will always be arbitrary, and leave one side in the dust.