WHM lost six things to Cross-Role but can only have five of them back at a time. So they're losing one of the following effects at any one time, period:

Shroud of Saints (1-1 with Cross Role, the new version's better)
Protect (was innate, now Cross-Role)
Esuna (was innate, now Cross-Role)
Eye for an Eye (from old Cross-Class)
Divine Seal (now Largesse from Cross-Role)
Cleric Stance (specifically the 10% damage buff)

It also had outright deleted:

Virus (from old Cross-Class but mostly a wash, no Healer has an equivalent now)
Stoneskin (gone
Stoneskin II (gone)

And also freed up four hotbar slots on top of that:

Stone I (Becomes Stone IV)
Stone II (Becomes Stone IV)
Stone III (Becomes Stone IV)
Aero (becomes Aero II)

And they technically "lost" another ability:

Fluid Aura's no longer a damage-weaving oGCD

So it meets the simplification quota almost entirely from the Stone/Aero crunch. But they didn't do like Paladin and go back to fill in any gaps, and it lost more stuff to Cross-Role than it gains back from Cross-Role.

That's where the disparity in abilities come from.

Number of abilities doesn't determine play experience. But having one Job with far less abilities than another (when you count SCH non-Petbar pet actions or AST cards) does give you less levers to pull. Both for Job balance and for distinguishing Jobs from one another.