This is absolutely true for some people but not a rule for everybody. MMOs have evolved and the types of people who play them broadened. S-E said people were begging them for fewer buttons so much that there's even some people who redo their hotbar each time they enter content at a different sync level. For some reason they don't want to use additional hotbars and can't fit all of their buttons in at once; they only bring the buttons they think are most relevant to the duty they are doing. They are for sure getting pressure from part of the community to consolidate stuff, not doing it out of ignorance or malice.
I will say though I think it's not the amount of buttons but what you do with them. MMOs can still be engaging with fewer buttons by shifting the complexity into other parts of the design and having the hotbar be more contextual, adapting it to offer only the relevant options you need in that moment. It's less intuitive to navigate a bigass spell list during what is pretty much action combat these days. When combat was more slow and thoughtful, tactical, it made sense. I like tactical games too but it's not this game. However healer dps specifically has always been boring in this game imo. That has been consolidated too much, even back at the beginning.