One of the biggest public accounting firms in the US had to raise salaries because of collective bargaining from interns. It works.

I'd rather not give too many details so I don't get doxxed. I was on a date with a girl interning at a big public accounting firm and she showed me the interns group chat. The interns received a pretty shitty offer and banded together to refuse to sign the offer letter. About 90% of the interns held out (based off the responses in the GC) and on the morning of the offer deadline the company caved and gave an almost 15% salary bump to all new hires. I remember years ago when someone tried the same thing in my intern group and there was no support for it, back then I didn't even support her. But seeing Gen Z pull this off is amazing and really woke me up to the fact that collective bargaining does work and that we need to push back on employers.