Wait I’m confused. What is there to not get?
Homogenisation is when they put stuff that clearly belongs on one job onto another, that makes them feel the same gameplay wise.
Like making all four healers have effectively identical filler attack spells with the same 1.5 cast time because they wanted to homogenise the role with AST’s faster casts (Glare / Broil / Dosis \ Malefic). There isn’t a functional difference outside of flat potency between any of these abilities, despite them existing on four different jobs. Un-homogenising them would mean giving them each unique filler attack spells that fit with the actual job’s design/identity and not just matching Astrologian’s cast times across the entire role lol. I.E WHM having a longer cast higher potency filled, SCHs could have a debuff attached, Astrologian’s could remain a 1.5s cast, and Sage’s filler could have a chance to proc Addersting or the Kardia effects could be different when Eukrasia is up.
I mean if we want the perfect example of a time in which the devs pursued homogenisation to the point it made the game worse, we need look no further than Heavensward phys ranged. They designed Machinist as a pseudo-caster with the ammo system to work around casts, then randomly decided to add cast times to literally every Bard weaponskill they had. There was no functional reason for it, no gameplay advantage, and Bard already had casts on their songs anyway. There was no need for them to copy+paste Machinist’s entire job gimmick onto Bard, but they did it solely for the sake of ‘homogenisation’ - to make them play and feel the exact same.
Why do they choose to ‘homogenised’ classes by making them all do the exact same things in the exact same ways? That’s easier to answer. Easier job balancing lol