Oda had a perfectly good power system in place with devil fruits, all he had to do was not create haki and we wouldn't have this power escalation problem; fights shifted towards who has the better haki wins and since everyone uses haki in more or less the same way there isn't much room left for uniqueness, it's like in dragon ball where everyone fought the same way more or less and the villain of the week was stronger than last week because he did everything the same just better and haki is like that. Oda could've just stuck to DFs and had characters apply them in unique ways, like adding more dimensions to a shape; everything stays fresh and personalized. But Luffys new gear is definitely a step in the right direction, anything that moves away from bland haki fights and more of what early one piece had the better, besides the whole Mythical Zoan Sun God part......everything else about it is great.
But the major issue is the haki blooms. They're just free un-earned power ups that only Luffy really seems to benefit from.