Role Requirements

Too many games have been lost due to the enemy having a tank and not us. Too many of the ranged jobs, which is basically all of them with the exception of a few melee are rightfully too afraid of getting onto the crystal because they'll be focus and killed. There needs to be some sort of system in place that forces 1 tank, and 1 tank only on every team. Even at the expense of queue times. Maybe this isn't an issue at very high ranks but it's really hard to climb when you have a bunch of babies who refuse to touch the crystal on your team..

Its player mentality, not CC when it comes to that. the lack of duo ques and nobody paying attention to callouts in ranked is basically just people not really wanting to put effort in the mode anymore, cant say that i blame them!

In CC specifically, I consistently beat parties with tanks. Just gotta overwhelm them with damage and not target them if they use their invuln LB.
The lack of forced party comp is great and separates it a lot from The Feast.

No fixed team composition was pretty much a major selling point of Crystalline Conflict over Feast, so it's unlikely that will change. Personally as a melee DPS main, have tanked far more damage than many actual designated tanks during matches since starting the mode and I can vouch that it is still possible for melees to fill the role if they're willing to sacrifice their own uptime to do it (Not ideal though!). However; this requires your team to be really on your heels and keeping the pressure up, as you will melt the instant you get stun-locked which can happen super fast depending on a number of factors, most typically server ping disagreeing with your defense.

Won't deny though that some compositions I've seen in some matches have just been brutally unfair to fight with, it's not common to get an extremely lopsided composition, but it can happen. Just advise people to actually be ready to support your main line, once a melee DPS has lost their Guard, they will need to retreat fast, so react accordingly else the death train will ensue. And try to stick together if you're ranged, if you don't: that's a freebie for sneaking ninjas and escorts, if you don't see them, rest assured they probably see you.

For offense, focus fire the enemy that has the most potential to lock down your fighters, or is a quick enough kill. I strongly advise people to make use of the focus target feature, and try to keep an eye on markers if someone's trying to coordinate. Above all, stick together (but not too close if the enemy has massive AoE crowd control potential) if you find yourself in a very ranged centric team, and make sure your few frontlines (plural being optional) can at least get out of line of sight of the enemy, they will undoubtedly be chased so be ready.

Bump. CC doesn't need a set enforced party composition, but the MM should have some adjustments made to it to try and provide an even role distribution between teams. There are some huge advantages and disadvantages when you have a role (healer/tank) that another team doesn't and that kind of team RNG shouldn't be present in a ranked gamemode.

Just to add, I'm not counting melee vs ranged dps when I say roles.