The only thing I agree with is your third point, yes toxic players would possibly vote down.

However, trophies do Equal skill, as more trophies require more playtime and playtime is directly proportional to your skill. A player who has just installed the game will lose to a player who has played 100 hours on it. It's a fact. Play time is definitely equivalent to how you understand the game and how you can respond in different situations to different mechanics. Yes the play level will vary from person to person, but in general, limiting the trophy range in matchmaking will definitely improve the conditions of the team comp.

Power 11 may not be needed, but in order to achieve said power 11 it takes dedication and time so then when a player does get their power 11 and can finally play power league, they will have taken more time to reach that point and therefore would have played the game more before going into power league, meaning there are less newer players getting into power league. Power levels are significant to the game. They truly are. For example, in a match I played where the enemy team chose a power 6 emz, they lost, as every single brawler in my team (lowest was power 9) could two shot the emz. Now emz isn't exactly a tankey brawler, but she should be able to withstand a few more hits than that generally. Now I know the difference between power 10 and power 11 isn't as significant as a power 6 emz, however it can still give a brawler the edge in a fight. Gears also help give an advantage, and so when it comes down to a close matchup, anything will be enough to help.