Adventurers guilds in isekai settings

[holywhippet]

 Something occurred to me last night as I started watching yet another isekai type anime. Why do so many of them have an adventurers guild that the main character(s) can join to start earning money and doing quests? At first glance it seems perfectly reasonable - an adventurers guild seems like a standard thing to find in a fantasy setting. But isekai/litrpg are usually based on video games with the idea that the main character(s) have found themselves in such a setting somehow. I can't really think of many RPGs where you have an actual adventurers guild though.

Off the top of my head:

1. The Bards tale games. The adventurers guild was the starting point for each game IIRC. But that was just a place to create/replace characters. It didn't hand out quests.

2. The Elder scrolls games (Skyrim, Oblivion etc.) have guilds, but each are faction specific - mage, fighter, thief etc. They do have quests but they are for individual people or just for the guild in general rather than taking requests for the public.

3. Legend of Heroes (Trails in the Sky, Trails of Cold Steel etc.) has the Bracers guild but that requires training and qualifications to join and doesn't just hand out generic quests for anyone to take.

 Are there games I've forgotten or not played? Or is the adventurers guild mainly just a ploy device for isekai fiction to give the main character(s) somewhere to start?