This is actually a really well made vid that highlights a lot of the issues with valve and the game atm.
The only issue I think might not have been brought up enough is the actual lack of diversity in specialist roles- 3 defense specialists and 2 pick specialists that are easily counterable by holding certain positions doesn't exactly do much to alleviate stalemates but yeah valve probably won't do much to change that.
Another issue with valve being slow is that people are going to be less willing to allow everything or accept changes that seem like they might lead to a worse meta when the balance changes might come 18 months down the line. Contrast to CS or Dota where players are able to deal with a worse game for maybe a month when the effects of these changes become extremely apparent in their highly viewed competitive matches.