What keeps a modding scene alive long-term: the tools, the servers, or the creators?

I’ve been around the GTA modding world for a long time, and one thing that always struck me is how SA-MP kept San Andreas alive for a decade after release. The base game stopped evolving, but the community around it never did.

Watching FiveM do the same thing for GTA V now has me wondering what the actual ingredient is. The tools obviously matter, nothing gets started without solid modding tools. But tools alone don’t keep people coming back for years.

So I’m curious what people here think: what is the one thing that keeps a modding scene alive long-term, the tools, the servers, or the creators? My gut says the servers, since that’s where the community actually lives, but I want to hear other takes.