No one suggested that. Like literally no one.
But if you think number of skills makes for complexity, then try Everquest 2. My Shadowknight used 3 hotbars of active skills (36), half a hotbar for potions and consumbales (6), and 1 and a half for buffs (18). Thats 60 buttons. Combat there was much simpler than FFXIV, and even ESO where you have like 6 skills.
We don't want less skills. We want less hotbars and buttons.
I suggested a system that uses combos similar to mudras, which would introduce quite a bit more skill (maybe even more than the average player on this forum could handle) than simply pruning abilities (it doesn't prune them).
Imagine if you had Cure, Cure II, Cure III and Medica, while pruning away Medica II. If you use Cure, then Cure II. When you use Cure III it is a large single target efficient heal. If you use Cure then Medica, then Cure III, it works like it does now. If you use Cure, then Cure II, and then do Medica, it fires off an AOE regen like Medica II did.
See what happened there? I actually introduced an extra ability compared to what we have now and pruned one off the bar. So instead of 5 abilities taking 5 buttons. I have 6 taking up 4. And who would have thought to use Combos like that on a WHM? And if you need a Medica II spell immediately, then that is what Swiftcast is for. Can even tie Swiftcast (likely a crossrole candidate) to immediate getting the 3rd level combo out in a spell. Could even remove/reduce the cooldown on Swiftcast and just have it increase the MP cost of the spell its being used for.
Do something like this for all classes, as well as condensing spells/skills and you could EASILY reduce the hotbars to under 15 per job and role while still having over 25 skills. For example, condensing Kiss of the Wasp and Viper into one skill. Using the skill activates Wasp, activating it again activates Viper, and then doing so again puts Wasp back. Again.. 1 button, two skills. Can even add a third poison into that little rotation if they wanted.
Speaking of Ninjas. They could put Mug's effect into Assassinate and increase the potency. Still have the 'two' skills, in one.
Everything I mentioned doesn't make the game easier to master. Just easier in a physical sense to play. And the benefit is less hotbars, more screen real estate.