The difference here is f2p vs p2w. p2w mean Pay to Win. There are many P2W FPS type games where you can buy weapons that give you an edge over those without tho

The difference here is f2p vs p2w. p2w mean Pay to Win. There are many P2W FPS type games where you can buy weapons that give you an edge over those without those weapons. In some cases, you can 'unlock' these weapons by earning in game credits, but often the amount of grinding required to get there equates to months of game time. In DOTA2, LOL, and TF2 the micro-transactions are generally restricted to cosmetic / vanity items. These items offer zero competitive advantage.