League was the first free derivative of the mod (Dota 2 was released nearly four years after it) and the complexity of the game was massively reduced to the extent that it's marketable in a way that Dota 2 just isn't. Valorant is trying to fight the incumbent while dealing with an inevitable balance trainwreck, and although Riot is going to throw a lot of money at it, it's not clear they realize how spoiled they were with the success of League. I'm sure the game will be around in a few years, but the odds of it largely supplanting CS don't look very good.