Eh, it's a big galaxy. You've also got the Tollan, the Nox, and the Aschen running around in their respective parts of the galaxy.

There were, what, roughly 210 episodes of the show? So we're picking about 200 random places out of 100 billion stars. There's still a lot of room for entire Federations worth of stuff in other parts of the galaxy (sorry to cross fandoms for that comparison, lol).

I mean it definitely happened too quickly, but from I remember it was mostly planets that were formerly under Goa'uld occupation that started using their tech. I never could figure out how her father was some kind of smuggler/swindler since she ended up getting taken as a host and must have been under their rule.

I've always been interested to know how the four races ended up losing contact with each other. Actually, how the hell did they even find the Nox to begin with? They only occupy one planet from what I remember.