[ArnoVW]

There's a pattern where criminal organizations fill governance gaps rather than starting as genuine governments. The Yakuza did this opportunistically at certain historical moments. Hamas is a similar example (not a criminal organisation, but..) , allthough they are more of a institution-building than the Yakuza ever was.

[dudefeliciano]

Mafias generally fill the same functions of the government but for the underworld: providing "protection", extracting "taxes", enforcing rules via the use of violence, and so on.

[Pay08]

Probably the best example of this are American mafias.

[lazide]

Yes, it’s a big reason why they have always tended to be based out of immigrant communities - those were excluded from mainstream culture, governance, etc.

If you were mainstream you didn’t need the mafia - you were already the gov’t, the police, etc.