The ultimate crux of the issue is that Labryinth & Srycus are way undertuned compared to the ilvl you get synced at resulting in every group skipping all the hard mechanics of every fight (You ever seen Glassya's jump phase or even the robot adds since like Stormblood?) Void Ark sorta suffers from this, Rabanstre technically suffers from this too but the mechanics there are also way more punishing than in the CT raids (*cough Hashmal everytime I get Rabanastre cough*) WoD is technically a bit undertuned, but people love dying to the simplest things on Angra Mainyu & Cerberus en masse so I think it evens out a bit.

Honestly, I think they just need to make Srycus & Labryinth force an ilvl sync (and a strict-ish one at that, maybe like i70 & i90 respectively so that all the hard parts of the fights suddenly come back and the fights cant be steamrolled anymore, and the total time of the instances goes up by 10-15minutes due to far less damage happening. Make the two of them take as long as the rest of the raids & far less steamroll-y and people will stop trying to strip if the easier raids are actually the higher level ones.

That being said, no matter what you do, Lab & Srycus are going to appear more often than all the other raids, statistically. They're the only raids mandatory for the MSQ (Whereas Sky Pirates is totally optional and Ivalice is only mandatory for SHB relic, and copied factory will only ever pop if you're 80 and get lucky), so everyone will have to have them unlocked at some point or another, They're available at level 50+ so they have the highest level range of players that can be put into them (doesn't matter if you're 79, if someone the DF pairs you with is only 59.9, you're getting a CT raid due to them). It's just a simple reality that statistics favors CT over any other raid due to all the factors involved, before the naked queue-ers are even factored in.