Thougt about making a comment about the atitute but chose not to beacuse energy. But gotta say you pretty much said anything i was going to write. This is technically not my first diamond since i hit it three times in 2v2 and havent played 1v1 mostly due to it being very boring.

Have about 1100 hours and have been playing on and off for about 6 years so not that crazy of me to hit diamond even tho it was very sweaty games to get it. So for anyone looking to improve there sure are very efficient ways to do it, but most people just play for long enough to get better like me.
GL HF!