There's already regulations (or industry rules) regarding money laundering, credit card processing, credit card charge backs, international money transfers, etc, etc. That alone creates a decent barrier to entry.
Then there's other issues such as merchants lying, customers lying, refunds, stolen accounts, etc. PayPal closes accounts (and so on) as a consequence of trying to deal with all these issues.
I'd posit that PayPal does not suck because it's PayPal but because of the product itself and anyone who tried to fully replicate it would run into the same issues (and thus suck just as much).
https://twitter.com/nickmon1112/status/1076886857445711872?s...
Long twitter thread on the relation between MasterCard, Visa and Patreon and how the credit card cartel is attempting to minimise political risk.
Specifically, what's stopping a competitor
from eating Paypal's lunch right now?
I only hear people bitching about their paypal account being locked once or twice a year, whereas I assume paypal deal with hundreds of attempts at credit card fraud, chargebacks, complaints about ebay goods and suchlike every day.
On the flip side, if we did get new laws, why would the goliaths not use their country-size budgets to lobby for the laws to just ensconce them as the government-approved monopoly (maybe not directly, but for example by throwing up legislative barriers to entry against would-be competitors)?