As an example in Warcraft 3 you have a decent level system. First you go up to like level 25-30 then stay there for a while until you learn how to play properly then eventually go up to levels 35-40 which meant you're pretty good.
In SC2 there's was decent ranking system as well. You play constantly and you see how you go up the ladder, eventually you get transferred from bronze to silver then to gold then to plat etc.
Overall you play and you see the results. Like before I was lvl 20 in WC3 or in bronze SC2 and now after a year I'm in plat or diamond, or have 40 lvl battle.net. That boosts your confidence and you see that you are actually making some progress, you improve.
I feel like SC:R battle.net does not have this at all. I started playing a year ago (never played BW before). I play almost every day and my MMR stays the same all the time. When I just started it was around 1100-1500 going up and down like crazy. Having over 1000 games played it's still the same. MMR goes around the same range, never goes higher than 1500. Most of the time around 1250-1400 range. I face the same opponents. I win the same people and lose to the same guys. It's like there's a wall you hit every time you go closer to 1500. Something happens around this MMR (maybe smurfs of pros) and you drop down with like 15-20 loses in a row sometimes.
I feel that (subjectively) no matter how long you play you just stay exactly where you were all the time. I don't see any results or any progress. It's hard to say even by past replays whether I played worse or not. I wonder if it's possible to improve eventually over the years without devoting to the game 8-10 hrs a day like Koreans do. It's very frustrating..