From recent personal experience FRiend, I would have to disagree. The last 3 years in my exact same position/responsibility, non-union job were:
3 years ago - loss of $150 per month
2 years ago - gain of $50 per month
1 year ago - loss of $30 per month
All due to supposed market adjustments in my field. Which, is and was horse crap. Especially since I personally knew people in other states doing a same but lesser job than me, who were making a lot more.
I got a union job at the same company, and bam! Instant raise, and a good well funded retirement.
There may be benefits to union membership.
But the biggest benefits have been taken over by the government, IMHO.
That does not mean you are at all wrong in your experience.
We likely agree much more than we disagree.