Top-level management doesn't even have to be "the enemy" for a union to be very nice to have—companies of more than like 30 people are gonna have a shitty, abus

Top-level management doesn't even have to be "the enemy" for a union to be very nice to have—companies of more than like 30 people are gonna have a shitty, abusive middle-manager somewhere and a union gives employees cover to resist their bullshit at far lower personal risk. "No, I won't be (coming in on Sunday/'just doing this one extra thing before leaving after hours'/breaking company policy and legal requirements for safety or waste disposal or whatever), please see [section of union agreement], if you'd like to continue this discussion I can bring in my rep and, as required by policy laid out in [other section of union agreement], your boss, and we can all have a chat about this" will get a lot of abusive pricks to tuck tail and STFU in a hurry, with low risk of effective retaliation.