I fundamentally disagree with this statement. I don't think you can say with absolute certainty that it "has a high chance to make it worse". Where is your data/insight/examples to support that claim?
While I think it's great you think the formula works, you'd be remiss to say there isn't a staggering divide in the community. There are those that think it work and those that don't. In all my years gaming (10+) I don't think I've ever seen such a stark divide in any community. Even in WoW the communities are generally pretty aligned when something is off. Whether or not that feedback is valuable or acted on is entirely another issue though.
Speaking strictly personally the combat engine is one of the larger issues holding the game back. It's too rigid and binary and holds back jobs from having other more in-depth synergies in their kits and encounter design from being nothing but jump ropes. More choice would go a long way and allow encounter design to better utilize deeper kits. I.e. let me make decisions about how much damage I want to take organically rather than by toggle. Let the flow of combat and party skill give me options to tailor my ability usage to support my team. I don't want to have to disband because both my healers sniff glue. Let me shift my resources to help bring the healers up. Make more soft enrage design than hard enrage, things that slowly overwhelm you as you fall behind, but allow for clever recovery.
That's not even going into the "formula" aspect, the thing that makes every iota of content we get predictable and stale on release.
Then there's gearing. It's probably the most boring gear I've ever seen in ANY game I've ever played. Secondary stats that don't actually tell you how much they improve by? Secondary stats that really don't mean anything? Gear that has so much "raw" data attached it to it causes server problems? Let's not even get started on the mess that is materia. The implemented materia system MIGHT have passed for decent design in 2004. Not good design, but decent design. It's 2018 though.
How about the "combat overhaul" where they managed to take cross class skills and turn them into something EQUALLY as useless and contrived? Cross class skills were an awful implementation (not an awful idea, but an awful implementation), and they managed to make an equally awful implementation in Role Skills.
How about side content? I mean I am not even a game dev by design (I do SDLC stuff though in the fin industry so I am familiar with dev). Side content needs to be robust. It needs to justify itself as a standalone piece of content that keeps people coming from other stuff is slow. Yet, every piece of side content is even more shallow than the main game, which is an achievement to be honest. And not a particularly good one.
The thing is, I could literally go on all day. That's not to say the game doesn't have GOOD aspects. It has a ton of those. Don't misunderstand my criticism for "hate" or tell me "this isn't the game for you then". I am passionate about the game and the universe that's why I'm so critical. It's because I care and want to see the game be better than it is.