Oda has systematically retconned all forms of haki.
Luffy trains all three forms to decent standard on the island, is dodging lasers with precog, knocking out 50000 fishman with no negative effects his side, and there is no distinction between the basic barrier haki that fodder sandersonia used and colourless CoA used to touch logias.
Suddenly CoO doesn't do that anymore and you need future sight to actually have mantra like dodging- and only on fodders if you are a protagonist.
Suddenly there are multiple levels to CoA that are needed, and can be learned in a few weeks rather than 6 months Luffy was left to "teach himself".
Suddenly CoC is only used in punch clashes, and only really when the other party initiates it, heaven forbid Luffy CoC clash on some non CoC using loser.