The truth about SWF
First, the elephant in the room, SWF with comms will give an advantage compared to a solo q. This is a fact, indisputable, end of story.
BUT, that does not mean swf is the boogieman it's made out to be. The fabled toxic 4-man isn't really a problem. In fact, I find the opposite true, most 4-mans tend to goof off far more then a group of 4 solo's, making them easier to kill. They also play stupidly altruistic compared to randoms. Also the gen rushing death squads who know all the loops, are fairly rare. Will you get the occasional rude, stereotypical 4-mans? Sure, it's likely you'll run into many different play style's and players, toxic people among them.
In truth, most of the time SWF is just used as a excuse for a bad experience. I played badly? Gen rushing 4-man SWF. Got a rude person in post game chat? Toxic entitled 4-man SWF. Rarely, in my 1000 hours of playtime, have I seen that be the rule, not the exception.
So really, SWF doesn't need a change, it's fine as is. Could the solo experiance use some improving, yes, I believe so, but it doesn't mean the opposite is a problem.