I'm not really looking for hard challenges from dungeons, but as a DPS player I do wanna have to use my brain a bit. It seems like for the most part, doing wall-to-wall depends on the tank+healer, and not so much the dps. The dps has to kill the stuff quick enough, but unless it's super egregiously bad dps, if the party wipes because the tank ran out of CDs when the fight dragged too long, the blame's probably going onto the tank or healer.

Bosses are largely fine, they have actual mechanics to do. They're not tough, but they're there.

I'd just like more trash pulls that require people to acknowledge what's going on beyond avoiding orange circles. For example:
-Add an interruptable ice spikes mechanic to a certain mob in a group. If the DPS ignores it and keeps on aoeing, they eat ice spikes + either die, or get a damage down, or something. They gotta look at the enemy list, interrupt it when it starts, and then go back to AoEing.
-One mob that tethers/covers another mob, and that mob starts casting a big spell. You gotta focus the covering mob, so you can kill it before the other guy gets off his big spell. The spell probably gives damage down if it goes off.
-Players get a buff that makes it so only they can attack a spooky ghost enemy, or something
-enemies that hit softly, but give stacking vulns to the player they hit, so that the tank explicitly has to let the dps/healer tank it
-enemies that explode with decent unavoidable damage/stacking debuff when they die, requiring them to be killed single-target (like cochmas in sephirot ex) to avoid stacking the damage/debuffs too high
Not all of these at once, mind you, just put one in each pack or something.

Really, they just need to put in mechanics that you need to acknowledge, and which give damage downs as a mark of shame when you mess up. Especially in a roulette, DD stacks are a great way to show people they're messing up, and incentivize them not to, without just making it actually a lot more strain on the tank/healer who have to heal them more/etc. I'm not looking for roulette dungeons to have mechanics that need raidplans, I just want stuff that isn't so easily brute-forceable that SE had to implement more actual walls in dungeons to keep people from trying to bruteforce dungeons so hard.