The FGC stems from the arcades.

• Many countries still have an existing arcade/gaming scene.
• Or the ability to own console/pc hardware is a little more rare. So it leads to players coming together to enjoy competitive games together.
• Fighting games can get a lot of people rotating on and off a station pretty fast. So everyone gets to play.
• No teams, so the schedule can be regular and open entry.
• You can scale events on the fly to the number of entrants.
• No need for major sponsors or huge amounts of money to even run a local.

This all translates into events where people from developing nations without tons of money can get into.