It's a bit of a stretch to equate Paypal with "all American transactions." There are of course Visa/Mastercard (variable but about 2%), debit cards, Venmo, and older bank transfer technologies (ACH).
A service that costs a fraction of a cent to perform but charges tax on total revenue plus a big old fee has a big barrier to entry or it has zero customers tomrrow.
"all american transactions" - who cares what proportion it is? It's the most vulgar display of market power imaginable. "We will tax this large chunk of the economy." And I'm not even seeing anyone saying they won't get away with it.
Would you propose a national price cap on transaction charges? It would be hard to justify intervening in this way, given that there is plenty of competition and rates are not very different. Any transaction (even cash) has associated costs.
I'm yet to find a European that complains about the EU's caps on interchange fees for debit and credit cards. Is a regulation like this unfathomable for most Americans?
Folks in the US are so used to corporations stepping on them a balanced discussion about this (where both parties agree that you being exploited is not okay, but maybe disagree on the solution) is no longer possible.
There is already Bitcoin with basically free Lightning Network transactions, so it's more like people vote with their wallets that they prefer (at least for now) paying this 3% tax instead of few bucks per year for channels opening/closing. And it works in the same internet market (real life and cards is a bit more complicated because of existing payment infrastructure).
So nobody force Americans to pay, actually, they do that voluntarily.
