Whether or not you are presently in a Union, Unions and their work rules and safety standards, etc., have already affected you and your job.
Basically, Unions set the standards for this stuff. In my industry, pilot on-duty hours are a direct result of Union research, lobbying and efforts. And we considered it a "success" when we got the maximum limit to 15 hours on duty.
Now, in the clear bright sunshine when everything's working fine, 15 hours on duty will leave you plenty tired but capable. In the dark of night, in the middle of a thunderstorm with one engine shut down and a hydraulic problem... it'd be better if your crew was fresher than that.
Still, I can remember being on duty 18 hours in the early days.
That's what Unions do.
OTOH, Unions can be simply ridikuloose. I remember when they wanted to keep the Flight Engineer on the B-737. That's featherbedding pure and simple. NO ONE benefits by being intentionally inefficient. Far better to accept the new technology and help the company maximize profits and thus GROW, providing new useful jobs for those 737 S/O's.
But rest assured, Managment would/will push to the extreme if it will fatten their bonus check. On duty 55 hours? Where's the problem? They'll never see it, because they only see dollar signs.
Again, though, Unions will push to the other extreme.
In short, the job you have, the balance you have stems either directly or indirectly from the Unions.
If you think the government will cover your butt, just look at Fed duty rigs for Commuters versus Major airlines. The job of a Commuter pilot is, if anything, tougher than flying for a Major. But their rigs are MUCH worse. Why? They came late to the Union, too late.. and the Government da n sure didn't look out for them. Their rigs STILL suck and they've had Union help the last few years. They're getting better, but they have a long way to go.