It sounds to me like a matter of preference & taste. Though Overwatch has won more awards, League has more players & draws a bigger audience for competitions. Do you prefer a multiplayer battle arena game, or a multiplayer FPS? Do you like medieval/fantasy style or futuristic, post-apocalypse style? A gamer has told me it’s easy to understand game play as a newbie in Overwatch, though challenging, skill-wise; conversely, they said of League, “I was basically just pressing buttons fast & winning, and I didn’t know what was going on.” As to why Overwatch has won so many awards, it sounds like the development team was small, nimble, and had an unusual degree of creative freedom.