In the UK at least, there's also quite a few people working on 'reinventing the union' (e.g.: https://www.organise.org.uk/ [1]). There's definitely an element to which old-school unions aren't particularly well suited to the modern workplace.

For example, they don't work very well for freelancers/gig economy type jobs; and their traditional focus on job safety in factories/assembly lines doesn't really apply in the same way to programmers sitting at desks.

[1] I'm not affiliated with them, but have met the team, and they seem like smart people.