EU only has 4 of the top 50 banks by market cap. the us has 10. I'm not saying the us system is necessarily better, but for two economies that are comparable in gdp, that's a big gap.
https://companiesmarketcap.com/banks/largest-banks-by-market...
https://companiesmarketcap.com/banks/largest-banks-by-market...
Supposedly, many countries in Europe require banks to have at least 100% collateral of deposits, this should mean resolution in the case of failure be much easier + bank runs less likely to happen, as people can feel safer that their funds actually exists in the bank is liquidity. Unless the bank is operating fraudulently that is.
US is also the investment capital of the world, so it's quite unsurprising.
1. Indirectly - which group do you value more: investors or depositors?
the exact opposite is true. excessive concentration means an oligopolistic or oligopsonistic sector that is holding everybody hostage: clients, employees and the political / regulatory system at large
adulation of "bigness", if not with ulterior motives, is naive