The postal service runs functionally craft unions that don’t negotiate together, Rural Carriers bargain separately from City Carriers, who also are separate from the APWU which covers clerks and maintenance folks. There are upsides to this, for Rural Carriers specifically it let them get certain contract items that would be a huge ask to get for other carriers due to the specificity of their job requirements, but it’s led to a problem where regular rural carriers are in a pretty unique bargaining position relative to virtually everyone else. Importantly, they’re also divided into full time regulars and part time RCAs, which I think creates an engagement problem. When I was an RCA I paid dues, but I rarely interacted with or cared about the union because it was pretty clear pretty quickly that the union was mostly concerned with the regulars who had been there a long time. It was likely to be upwards of 5 years before I became a regular (I knew people who had been working part time for 7 years) and almost all the perks and benefits were negotiated to benefit the regular carriers.
I think over time new regulars are becoming less engaged, especially since there have been recent changes to the craft that undermine a lot of the promises that were ostensibly the reason you waited in line to become a regular in the first place. So the leadership is getting increasingly detached from the actual workforce, and the union is already one of the smaller and weaker ones to begin with.
EDIT: A bigger problem which I probably should have mentioned to begin with is that all postal workers are legally barred from taking a strike. So the unions have something of a more collegial relationship with management than you’d like, because you can only play hardball so far before you run into legal trouble.
Whenever I find out about the next movie Disney is doing it feels like they’re just dabbing on their fans. I quit following this shit years ago and have adblocked my life pretty thoroughly so I don’t usually know what’s going on, but every time I get a glimpse I feel vindicated for checking out.