Why is this mod so popular?

well, maybe it's my bad but I haven't played garry's mod ever.and I wonder why this mod is so popular. what is your opinion?

Well, you can create anything you want! Either by building it or coding it. Also you can create communities here, some are cancerous tho...

You can make anything you want, play anything, build anything

I assume it's talking about Garry's Mod?
Well because you have a vast variety of what to do, whenever you're bored, just pop up your TTT or Prop Hunt and find a server that's fairly populated and go have a good time!

Because it is simply amazing
Garrys mod is one of the best ever

I think it's popular because it's a sandbox and there's a lot of addons for the game.

because it is limitless so you can build many different things buy building it with props or by writing it (coding)

I dont know to be fairly honest with you. I guess I will try and take a look but I cant promise anything

It doesn't limit you at all. Create everything you want, a huge workshop and an easy to learn scripting language are the essence of Gmod

You just have near endless possibillities. Play sandbox and make your own creations or download one of the coutless addons from the steam workshop. Then you are able play one of many gamemodes, like DarkRP, TTT or Prophut.