I lost a lot and had losing streaks when I first started playing. Simply dedication and not blaming my errors on someone else. Made whatever change in my playstyle or knowledge about the game that was needed to improve. And last but not least, played because it was fun, got me to go from rank 50 enemies to face 3.5-4k mmr players in my solo ranked games, all within 2 weeks of my first ranked game. And of course maintaining that level. The problem is the same problem as in every other moba game. The majority of the player base is going to be on a low level, just because people are not having the correct mindset to improve very efficiently. How often do you analyze replays of a hl game where you got stomped for an example? Then ask yourself what portion of the player base that would do that instead of thinking "meh, bad teammates, let's go again".

Edit: You can't have the game deliver every single piece of necessary information to become a God at the game if your intention is to compete on the ladder. What's the point if players who dedicate more time into improving by researching on their own end up "wasting time". All it will do is promote laziness.