Why is darkrp so popular?

Sometimes when It comes to specific darkrp servers, its the staff, the mods, the map, and performance. Biggest being the appeal of what one server has over another. In some cases that just the player base. Some servers luckily happen to have really cool people which attracts even more people making it super populated. But thats a little rare to find when making a new one. Its a fine soup of luck and determination.