I feel like there are two pathways to getting that first post-doc after finishing your PhD. The first is to know the right people and be lucky, and the second is to have the right skills and be lucky. Note that there’s a substantial amount of luck involve in both these pathways – lucky that your project was relevant, or your skills were relevant, or that you weren’t sick, or that you finished at that time, and so on and so forth. Sure, you need hard work and connections, but if you can miss the deadline on something just because of some unlucky event.
PhD candidates that know the right people and are lucky typically follow a similar pattern (note: anecdotal). They make connections in their group, in their institution, and at events in their target area. They collect skills and proven work relationships; they are reliable. At some point near the end of their candidature, they start approaching people to see what positions are available. If they’re lucky, someone will have something. Boom! That’s there first post doc, and nary an application form was discussed or seen.
Candidates that don’t match that pathway have to find positions and apply for them, fighting the whole way. Getting through at this point also requires luck. Of course, the more desirable skills you have, the luckier you’ll be.
It’s not fair, of course, that someone can get a job just because they know the right people or they asked the right questions. It’s not fair, but it is understandable. Think of it from the perspective of hiring entity: In this situation, you probably won’t get the absolute best person in the world, but most jobs don’t need the best person in the world. They need someone who is capable, pleasant to work with, and is proven to get the job done. Going through a hiring process filters out who is capable or not (mostly), but it’s basically impossible to know if someone is ‘pleasant’ to work with.
So it sucks for the people who weren’t lucky enough to get something out the gate, but I get why it happens. And really, it’s another reason why PhD candidates need to brush up on their social skills and be seen at that networking event.