Yeah bro we should make gear even more streamlined with even less choices.
And what are you even saying? jobs already have faster GCD based on the job, namely
Monk passive (Greased Lightning); Samurai sustained buff (Fuka); Ninja sustained buff (Huton); Reaper temporary rotational burst (Enshroud); Bard temporary buff (Army's Paeon); Machinist temporary rotational burst (Hypercharge); Black Mage temporary rotational burst (Leylines); Summoner varying rotational cast/recast times (Garuda); Red Mage temporary rotational burst (melee combo); Astrologian temporary rotational burst (Astrodyne).
And there's different BIS for different GCD depending on class u play. but substats in this game are already a meme.