European unions are completely different from US unions in how they act. UAW is the only car union in the US and recently had federal probes and they arrested like 15 people in the leadership (they were using union dues to buy ferraris, backyard pools, and other such things). They currently have a federal monitor making sure they reform.
UAW is the union trying to organize Tesla's plant.
I should also note that almost all Japanese auto companies in the US are non-union and it's been that way for many decades.
Another thing worth noting is that European nations have mostly nationalized labor laws. Worker’s rights which unions are bargaining for in the USA are national laws in countries like Germany and—to a much greater degree—Sweden. In Europe if you want more paternity leave, you don’t ask your union, you vote for a labor friendly party. Worth noting is that corruption also exists in unions in Europe. So corrupt union leaders is not enough on its own to spin a narrative where unions in America are uniquely bad.
If the narrative that unions hinder business growth was true, you have to provide with some mechanism for which that would be the case. An easy one is that businesses have to spend more per workers and hence cannot afford bigger investment. This sounds right, but it is anything but. If that were the case you wouldn’t see Volvo factories still operating in Sweden.
What is it precisely that unions in America are doing which is not a national law in Europe, and European unions aren’t doing which causes businesses “to wither and stagnate for the gain of a privileged few”?
UAW is the union trying to organize Tesla's plant.
I should also note that almost all Japanese auto companies in the US are non-union and it's been that way for many decades.