"Dues deducted from paycheck" and "typically must go through union instead of your supervisor or manager" are true. At the same time, they're minor inconveniences compared to what a bad employer does to you.
As I said in another comment, my dues are automatically paid through my PTO account which in turn is paid into by my employer. So yeah, it's still my money, but it's not coming out of my paycheck at all and I honestly don't even notice it.
At least in my area, most of your big trade unions have this as an option for members through the IBEW credit union.
It’s not always necessary to ‘go through the union’ instead of speaking with your manager. For pay, conditions and other disputes, yes, you’d want the collective bargaining of a union to get the best deal. For other things, it’s not always necessary.
I had a fall at work a couple of years ago. I fractured my ankle and was away from work until it healed and I could work again. When I returned, the problem area that lead to my fall hadn’t been looked at. I raised it with management myself and they dealt with my concerns and rectified the issue. I informed my health and safety union rep of what I was doing and he agreed to take it up if necessary. It wasn’t.
The company I work for has a long history of working with unions. They obviously have their motivations to improve efficiency and profitability but generally aren’t arseholes about it. The toxic culture I see in other companies only comes about when bosses can get away with murder because employees aren’t able to stand together.