I think a lot of workers might not know the process to go through. But its not hard to make a complaint this day and age.As you say "Not always". Insurance companies don't always entertain claims either.
But it's better than nothing - and nothing is what the remaining 90% of workers have.
No wonder the economy is going down the toilet.
My union has negotiated better conditions from my employer for 28 years.
Of course, non union members get the same benefits despite playing no role in attaining them.
IMV that's the norm, not the exception.
I dealt with a lot of unions round Sydney and nsw. Some really good guys and some really really bad ones.