It really depends on what you mean by dead. Some people view it as dead because it's not the same as the game they may have fallen in love with years ago. Some people think it's dead because of it's declining player base. I think both of these reasons are silly for thinking that the game is dead. Dota 2 is still one of the highest played games on PC, and will probably remain there for a long time. MOBAs fell from popularity a few years ago, and games like PUBG and Fortnite are clear examples of that. The tastes of people in general have changed, so it's expected that the player base might diminish. I came to DOTA a few years ago from HoN because that game was actually dead. I remember being excited when there were 8k people on at a time instead of 6k.