This is important. Clamoring for the return of 90 and 180 second buffs disregards the fact that during ShB, the jobs that were the strongest and had good synergy were precisely those based around 60-120s windows: SAM, NIN and DNC with SAM in particular staying at the top of the rDPS charts too, creating an imbalance, just like BLM right now topping the rDPS, nDPS and aDPS rankings.
This doesn't mean that the idea cannot be explored, but blindly going back to how it was without further thought would be a terrible move.
On the other hand, removing buffs from all jobs would have the exact effect. And there's also to consider that, if most jobs (let's say melee and caster) had no buffs anymore, then they will all be "selfish" DPS but that won't mean that they will all be equal because bursts will still exist and the damage of a NIN burst is not the same as a MNK's.
I think that we should have jobs with different DPS patterns (some with strong burst and weaker filler, some with strong filler and alright burst, some in between, etc...), as well as various burst timings (some having strong 60s, some being the strongest at 120s).
We already kind of have this with SMN, whose Phoenix phase is quite good, MNK's 60s having their strongest attack in normal encounters with full uptime, or WAR's 60s being mostly the same to their 120s. The idea would then be to expand on this so that not everyone relied on the 120s burst, as well as to provide different timers within each job and to make the filler phase not feel like a mindless 1-2-3 spam in some cases (e. g. NIN between bursts).
Why can't we have more jobs like BLM with less burst but continuous damage yet with the ability to pool resources to dump into party/single target buffs? Why is SAM's burst stronger than NIN's considering the former has a good filler while the latter lives or dies by their burst?