Paladin doesn't suck, 2 minute rotations just ruined combat

[Shurrikhan]

Have you played since legion when they removed more than half the skills and brought in borrowed power and started shifting to almost entirely a GCD system with very few oGCD skills?

Yes. Have you?

Two things happened in Legion:

1. Consolidation of non-integral flavor skills, often into more integral combat-useful skills (instead of reapplying Flametongue Weapon per hour, it became an additional effect on a rotational attack) and of cumbersome means of reaching a given capacity that taxed class utility for their maximal use despite their high opportunity costs (GCD-based stance-shifting on Death Knight in place of just a stronger mobility, defensive, and haste CDs).
2. To reduce "one-shot macro" play in PvP and animation-cancelling convulsions in general, many former oGCD CDs were given direct damage, too, but put on the GCD. That did not remove the number of CDs, nor the game's complexity for most specs (with just as many ending up notably more complex).

Rogue is probably one of the few nuanced classes left and they still suffer the same issue of heavy GCD limitations and almost no oGCD's and only a handful of skills.

Rogue has about twice the oGCD apm that it had pre-Legion, requires far more attention to combo point timing and usage in most competitive builds, and a majority of competitive builds tends towards more criteria affecting its APL than in MoP or WoD (i.e., greater complexity in decision-making) and stricter burst windows once a given string is fully setup (no more decisions to be made at that point, just execution).

Hell demon hunter is literally a 2 button rotation

7+ for any competitive build, and that's leaving out damaging mobility skills.

ret paladin is barely 4 buttons but generally 3 buttons on most builds

11-12 for the meta build.

By all means, it could be boring to you even when having higher apms and many specs requiring a whole lot more considerations than just adjusting string lengths (pretty much BLM only) and/or overclocking/underclocking a static rotation (mostly just SAM)... but your estimations are grossly out of touch.

A geared SAM could likewise consolidate its combos and play in single-target with 4 buttons and do better than terribly, but you wouldn't exactly call that the button count for the job, would you? So why the false or at least massively skewed narrative for your point of comparison? Beast Mastery is the only spec that's anywhere near to your estimations and it has always been that way, intended as a purposely easy/forgiving spec -- not just since Legion.