Most actively raiding DRK players in Heavensward also played PLD and vice versa. There definitely were fights that were easier to progress on with PLD than DRK, A7S being the blatantly obvious example. You see this decision-making reflected in the WF clears as well. WAR was the only constant in that they were good against all damage types. MNK and DK were completely equivalent to Delirium and were probably up even more often. You'd have to be playing with an incredibly subpar MNK for them to play without their blunt resistance down buff.

I wouldn't consider the proc-based gameplay on HW DRK to be 'tools' or 'utility'. It just ensured that your resource generation was more variable, forcing you to think on your feet. FFXIV players tend to be very much against any randomness or variability that prevent you from mapping out your rotations on a spreadsheet, which is why DRK unfortunately has moved closer towards PLD style faceroll rotational design despite being originally set up as resource management tank. The problem is that it feeds back into this culture that every pull that you do has to be able to potentially yield a mathematically optimal result (even if you're not at the mechanical skill level where you can achieve said result), or else we just wipe and reset until you get the numbers that you want. This was the kind of thinking that made them effectively remove Crit/DH from affecting WAR. It's an incredibly dumb design direction. Who cares if you didn't crit on your 22nd Fell Cleave? Just play your best and you'll average at what you should.