Working in a highly unionised environment I see both sides…
For: Its organised representation for a workforce with similar interests to communicate with a management who’s interests are not in line with the staff, it is also individual peer representation and support on local issues such as diciplinaries etc.
Against: Its self centred base level politics and S**T stirring for the sake of it, with no interest in individuals, and everyone knows someone at work who “knows whats going on and is respected”.
I wasn’t going to join the union when I started in my job 8 years ago, but when I had a H&S near miss and my manager just laughed and told me to deal with it, I joined GMB, who had a bit more clout than a spotty 22 year old who’d been in the job 2 weeks. Problem got assessed properly and was sorted. No one else had to lose any more fingers. Then a few years later GMB sold us up the river, all the reps got manager jobs and all the staff got shafted, so I left GMB.
few years later, lots of staff getting in trouble for insignificant things that have been tolerated previously(myself included), joined UNISON (after they offered the option of my membership funding unison only, not the labour party). Problems go away.
I’m sure I could get the same results by joining the 5 aside team (who play and drink with management) but I got a reduced rate on my mortgage through unison so all is good!