I am simply going to say that in my last job I was a part of the non union group due to the state I worked in. Every single one of our benefits was better than that of the union group. More days off, more personal days, more vacation days, better 401k. I made me wonder what the purpose of the union was.
Now when it comes to airlines unions are needed to negotiate contracts when the market has an oversupply of pilots, right now airlines are fighting for pilots and want to offer some things to attract more pilots but the unions won't allow without a complete change of the contract. I.E. Company wants to offer bonus or increase entry level pay to get more applicants through the door. The union says no because it doesn't help captains. So the end result is no one getting better pay. I would rather half get better pay than none. The result of not attracting new pilots causes regionals to cancel flights, canceled flights ultimately causes a loss of job of those that voted no to increase pay for half the group.
This also extends to contract amendments, Unions push the no vote for small improvements to reserve rules or benefits due to not including improvements for other areas of the contract or not going far enough. The only thing that forces a company to offer more is they see a need to, if they saw a need to offer 200% open time but not 250% voting no and leaving it at 150% causes no one to win.
A business will increase things as the market dictates, the unions at this point are slowing things down.