Bae'zel
Hero
Agreed. Again I recommend video game RPGs as setting a good example. Fighters Guilds!To me, it just shows missed opportunities for the other classes. Why not create an obligations table for each class or subclass that you can use to give all of them greater responsibilities in the setting? It’s not that I have a problem with restrictions or abilities with strings attached; it’s the “restrictions for thee but not for me” design.
Think about it: in a reasonably lawful society, outside of the military or police, why should anyone walk around as a human armoury without any checks and balances? Answer: Mercenary / Figthters' Guilds.
This does a lot: gives the Fighter a network to connect with in every settlement and plenty of potential NPC allies. As long as they fulfil their membership dues (whether in literal in-game costs or roleplaying oaths etc.). This would add so much world-building.
It is a wasted opportunity. This is why I think that "class" and "background" shouldn't be totally hand waved or trivialized by the DM. Don't FORCE players to do anything that they don't want to, but you can bet that I'd start my campaign elevator pitch with an explanation and hopes of player engagement with these ideas.
Edit: Guilds, cults, etc could be presented as an optional aspect of the setting that players can engage with at their leisure. The benefits are clear and you can even make them more substantial (once you reach Figther Level 5, the Guild rewards you with a Badge of Rank (advantage to relevant charisma checks with the military), discounts at Weapon and Armor smiths, and a ceremonial +1 Longsword or other weapon of choice) etc.