“Rabbis could even impose the death penalty on Jews who broke their religious laws, and sometimes did so”
ummmmm. no. the death penalty in Talmudic law can only be decided by a sanhedrin of 71 judges. There hasn’t been a sanhedrin since our temple was destroyed almost 2000 years ago. And if you study talmudic law, then you would know that the conditions to secure a death penalty are next to impossible to achieve.
Yet rabbis in Israel found a workaround. It's forbidden to lend money at interest, but acceptable for a person to "invest" in a bank. So when you deposit money in an Israeli bank, it's called an "investment," and the interest you get is a "return on investment."
This is why Israeli banks post a public notice inside to clarify that you're not getting or paying interest, it's all a "return on investment." That public notice is rabbinical mandatory.
Of course Jewish community leaders, rabbis, imposed the death penalty on their wrongdoers throughout the past two millennia. Why wouldn't they? Every community imposed the death penalty on certain miscreants. Why would Jews be an exception? Are they the sole people on earth who don't bend the law to their needs?
FWIW, I get all the above info from Israel Shahak's book, Jewish History, Jewish Religion: The Weight of Three Thousand Years.
You can also find it for free on Archive.org.