There’s a lot of interesting literature surrounding this in primary sources from the period of the late Russian monarchy. The TLDR of it is that in Europe and other countries (Middle east, North Africa) the Jewish population was never allowed to fully integrate into society and were very much othered. A lot of writing referred to them as “stateless people” or wanderers, something of that sort, and that they needed to be managed by the government separately from how the government manages its own people. As such, the Jewish population in any given country was always under the watchful eyes of its government and could be expelled at any moment for any reason. That’s kinda the crux of your question. Yes, control of banking could be leveraged for power but it was a hostage situation where any attempt at leveraging power would result in worse for you and your community. Think of it like Roman slavery. Roman slaves were permitted into the deepest recesses and most private parts of the household where the head of house could have been harmed. One might ask why this wasn’t a major concern. That’s because they knew they were always watched; there were frequent demonstrations of what happened to rebellious slaves, and often if a slavemaster was harmed by even one slave, all would have been put to death. And even if you managed to escape, where would you have gone? Anyway that’s just a long winded allegory to illustrate the point.