Gamescom was always really awesome with Riot there and it drew a lot of attention. There were so many cosplays (there still are tbh even without them) and a lot of people loved it. It was really a Riot event where you could talk to them and hear some awesome things about the game and its development.
Meanwhile going to lcs or worlds games is more like watching soccer games in a stadium. You go there for the game, have a bit of hype before the game starts and after the game everyone instantly goes home. It's not that much of a Riot event and not comparable to Gamescom.
External link →