Hardest in the game does not mean it’s difficult, just that it’s more difficult than everything else. I don’t think mythic raiding is difficult per say, neither is savage or even Ultimates. As long as you’re decent at the game and so is your party, you can clear after working on some coordination.
You’ve strayed completely away from my original point, directed towards someone else entirely, that FF is an extremely casual game and DBM isn’t required in the slightest. Almost everything mechanics-wise is telegraphed, unlike WoW, which is why DBM exists in the first place.