hank you for taking the time to express your desires.

However, I would sadly say that encounter and dungeon design has been simplified, along with general class design. Nowadays, most dungeons basically boil down to corridors you fight through. There are puzzle dungeons, and bosses tend to involve a lot of "dodge the orange fields."
Of course, this is just the observation of a casual player, but even as a casual player, I dislike the devolution of some of my favorite classes. Not every class needs to be complicated; some should be simpler than others. Classes should be different, after all.
Having all classes be simple is as bad as all being very complicated.

Some things one could do without changing much one example would be the tank rebalancing. Changing of numeral values on some of the tank classes.
Regarding encounter design, they could use more condition mechanics that the healer can remove with Esuna, which is something only a healer can provide. This could also counter the "no healer needed/wanted" mentality that seems to be prevalent.
Hard Version of Dungeon could also make a return, which would be optional but would deliver potential harder dungeon aswell.
There are more things one could mention here.
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At the End i will say we all want to enjoy the game and a lot of feedback over years got completly ignored which leads to frustration in a lot of people.