I must give a fair warning, this is a controversial suggestion BUT, if you read this post to the end, I will explain my reasoning.
I suggest one simple thing: ban Shotguns and Fusion Rifles from the competitive playlists(Survival and Freelance)
Now this alone is something that is bound to upset a lot of people, but hear me out.
The entire point of a competitive environment is to test your skill and victory is earned through skill(amongst other things, but that's besides the point)
Shadowkeep honed the competitive playlist by making it strictly 3v3 survival, which puts more emphasis on gun skill and map control, on top of all this they added this "true skill" system.
Shotguns and Fusions have no place in a competitive environment because they require very little effort from their user in exchange for an exceedingly strong benefit.
Furthermore, there is simply no possible way to balance Shotguns and Fusions to be in line with everything else without making them weak or underpowered.
Straight up banning these two types of special weapons will force people to use weapons that reward you for skillful play, instead of abusing the dominance of a handful of weapon types.
This is, to my knowledge, the safest and cleanest way to further improve the competitive playlists.
This is just one issue of many. There is very little skill involved with super kills. There is little skill involved with connection advantage. There is little skill involved with non-symmetrical PvP maps. Random weapon rolls give players an advantage if they have good RNG to get god rolled PvP guns. Controlling heavy ammo spawn areas is a fair thing, but it really just adds to an already 1 sided fight. If you already have map control, why have heavy weapon ammo spawn and increase their ability to control the map.
At a certain point you have to understand its just not a truly competitive game.