The distinction I'm making is one that spotlights the distinct control available to players via games like Monster Hunter or Metal Gear Solid, who have much more broad character control than tab-hotbar MMO's (Everquest, WoW, FFXIV). Characters in the aforementioned games (MGS, Monster Hunter) have a much more complex suite of actions/controls than any character in FFXIV could dream of having, given the limits of the system, but the actions performed by the players are inherently intuitive. Tab-Hotbar MMO's are disadvantaged in that every distinct action is a dedicated button, heedless of Context, character-state, etc.
Despite games like Monster Hunter and Metal Gear having far more freedom of character control and capabilities for actions, they are easier to control.
The point I'm arriving at is that without a sufficient solution in the engine for intuitive character manipulation, I'm not of the opinion that complicating a character's kit in a tab-hotbar MMO provides enrichment for the player. Before the solution of more complicated kits is explored, I'd rather years of development be spent gutting the entire concept of Actions/Spells as they stand now in lieu of a system of intuitive and bespoke character control, where class-expression then arises from artful and skillful expression.
I'd close with an example: Take a skillfully executed Ultimate in FFXIV, versus a moderately well executed hunt with 4 players in Monster Hunter; while observing the fight in FFXIV, what you interpret as skill, immediately, is the navigation of the fight's mechanics itself. You can't, as an observer, readily identify skillful execution of a job's kit. But you can see them navigating the mechanics and that is impressive. By contrast, whether someone is doing well or doing poorly (and as a player whether they feel fulfilment while playing) is immediately apparent in games like MonHun/MGS, both due to execution and navigation of an encounter. It's my opinion that to seek skillful expression in a game, doing so in the tab-hotbar MMO format is a flawed headspace, and we should seek to work within these limitations (leaning into encounter design rather than kit complexity), or forsake it completely and play a game where skill expression actually matters.