If your argument made any sense, you'd be using GDP per capita. And there the US is beaten by e.g. Switzerland, Ireland, Norway (skipping microstates) and all of them are around a decade ahead of the US in banking, at least.

There aren’t any.

I don’t think per capita matters in this particular case since the difference in gross gdp is so dramatic.

There is a much bigger incentive to monopolize in the US because the pie is so damn huge that it offsets the cost of overcoming regulatory hurdles.