Maybe, but Guilds are very much not Unions.
On the contrary, Guilds used to be where the professionals of a trade would decide who will be allowed to get promoted to higher ranks and who gets to run a store in town. If the Guild doesn't like your face? Tough luck, you won't get to be your own Boss (and in medieval Europe changing towns wasn't always easy either).
They'd also help each other of course, with no upside no one would join.
