My simple answer to the fireteam players who have had ‘free reign’ since D1 release is : fuck em.
Longer answer is;
Fireteams would and should be matchmade against other fireteams, which obviously means that those who have had a easy-mode of farming scrub solo players hastily thrown together to be killed repeatedly by them will now face teams made up of Twitch Streamers who go flawless every weekend, as well as all the other fireteams who have enjoyed the blood of scrubs for far too long, while saying to themselves “this seems fair and is working, they just need to ‘git gud’ and they’ll beat us”.
Bungie are introducing a pvp grind, for apparently a really good weapon, in the “competitive” bracket, which further rewards the established fireteams and will absolutely guarantee that solo players will avoid that bracket even more, and then the scrub-killing fireteams will be matched up against the streaming carry fireteams until they too quit the game in disgust, then they’ll blame bungie and the “TTK” for ruining Crucible instead of looking at their own behaviour for the past 7 months of non-stop slaughter of solo players who dared to queue alone into competitive (when Fireteams already had an ‘exclusive’ PVP mode every week available just for them called Trials…).