No, combat was a set pattern still. There was still an optimal rotation, assuming you could keep 100% uptime.
And it is that last bit that has caused (one of) the issues. They changed fight design so that you could keep 100% uptime, without really fighting for it. It didn't come straight away, but it went that way by the end of the expansion, which is why EW had virtually 100% uptime fights for melee.
Without downtime, you don't need to adjust your rotation, you don't need to think on your feet about what to do, what is the most optimal, how can I make the most of this downtime, especially on Monk.
ShB was also the time where people were asking for raid buffs to be aligned and how it was frustrating that some didn't, which leads into EW.
Now, to make things clear, I do not believe this design direction was dictated by the more hardcore groups, quote the opposite infact. It was the ones who were struggling who thought making things 100% uptime and aligning raid buffs would help them. This is also a similar philosophy when people ask for job changes. More often than not, it isn't the main players of jobs asking for changes, or, more specifically, bigger changes. They might ask for small, QoL things, but getting rid of positionals on Monk, as an example, noone who played Monk seriously was asking for that.
Unfortunately, it is this group of people who are also the most vocal, so it looks like more people are asking for these changes, when it is infact just a vocal minority, where, even if these changes are implemented, there is no guarantee they will even play the job.
This is then also why jobs feel 'samey'. Jobs do play differently, but the act they all play into a 1-2 minute raid buff window is why they feel they have the same structure. For the absolute extreme, you need jobs to break away from the 2 minute meta, easiest way to do that is to make each job selfish and have no raid buffs (however, I do know this is extreme and not to everyone's liking) and buy doing this, you can really make jobs feel different. You want that sustain job back? Sure, it isn't being crippled by the 2 minute meta now. You can also play around with giving jobs more tools to get around an encounter, especially now that they are not constrained by the party buff window (to elaborate a bit more, since every job is designed around 2 minutes and 100% uptime, all jobs get the required gauge and resources needed for these windows every time. By breaking away, you can free things up).
As a last comment from me, I have been enjoying being in parties where there are no party buffs more than in ones where they are present. As an example, Viper. If you get into a party with no raid buffs, you don't have to worry about keeping 50 gauge around when you go into the 2 minute segment and you can place this Reawaken combo wherever you want. It is that freedom to choose that this is a safe place to use it where it won't get interrupted by mechanics. It turns into more of a planning out of your 'burst' over the whole fight rather than having to constrain yourself to a specific 20 second window. But, that is just my thoughts.