[wffurr]

You said it yourself. Their capex is flat (in real terms?) and their marginal cost per transaction is zero. What happens to the per-transaction fee? It looks like it almost all goes to shareholders as dividends.

That's funneling money from the entire global economy into the accounts of a few wealthy shareholders and institutions in the west. That's pure rent going to capitalists just because they have the dominant payment platform.

No doubt that it creates economic value, that's why people use it! But a non-profit that charged fees just enough to cover operating costs would do just as well and leave money in the local economies where the payments are made instead of contributing to global inequality.