Is Gary's mod dead?

no its not, there are still like 50k players

No i dont think so, still we are having fun from gmod with my friends

I wouldn't say that the game is dead but to make a new community then I would its dead in that aspect

Gmod did not die, quite the contrary.

Not dead, I would say.
Currently, GMod lives on a monopoly of servers, that is what is killing the creators.

There's tons of servers still, but a majority is french or russian.
I would say the English speaking servers are in decline.

For me, Gmod is definitely not dead.
I'm still having fun in it and i think it could long for years

No i dont think so, still we are having fun from gmod with my friends

10 years ago it had way more of a user base. The age of average users has really declined with its overall user base.