Planetside was one of the most advanced games of its time.
Battles with hundreds, sometimes thousands of players all on the same map, and continents larger than some countries. It would take you an hour to walk from one side to the other. Huge raids with dropships and tanks and crack teams of 30 or so guys clearing rooms with chainguns and plasma grenades, while snipers on a hill pick off people defending a base so the armor can roll in. Epic air battles with gunships, interceptors, bombers and scout craft. Tanks and artillery providing cover for transports to roll into a base and drop off a squad to capture it. Probably one of the most epic, and organized MMO games of all time. People just wanted an arcade shooter, and didn't care to walk for 30 seconds from a spawn point to where the action was.
I still get chills when I see a screenshot of literally hundreds of people converging on some objective, with explosions and carnage everywhere.