There is one thing Job quests were good at that, that Role quests can never do: Justify and explain new abilities.

Take Summoner, for example. In the Heavensward questline, as we try to get a Ramuh-egi, it's explained that we're limited to three egis (I forget the exact phrasing, but it has to do with our aether capacity). Instead, we learn Trance (and later Demi-Summons) as a way to bypass those lore limitations, because that's what SE wanted the class design to be. But because we don't get Job quests anymore, that's where the lore is stuck: we only summon Ifrit, Titan and Garuda (plus Demi-Phoenix and the Demi-Bahamuts). Whenever someone suggests it would be neat to start summoning the other primals, people chime in with "Well, actually the job quest in Heavensward says we can't summon any more egis, so that's off the table".

I understand coming up with a full arc for each one of an increasing number of jobs is an untenable ask, but I think there is a compromise that could be had. I just wish each job got a single quest at the start of each expansion to lead into their new abilities. Let Y'mhitra take a good luck at us and remark that with what we learned since HW, and with what we encountered since then, our souls seem much more dense and summoning different primals might be back on the table. Or let us go chat with Hilda and discuss new techniques our machinist WoLs are thinking up and want to experiment. Heck, it wouldn't strictly need to involve old job NPCs (though getting to check in with them like in the level 80 quests was a fun plus)