I think the biggest mistake they made was making crafted gear soulbound.
It relatives all gear crafting professions regarding the economy/making gold. Yeah I can craft bags with tailoring and some other small things here and there, but the main aspect is only for you.
Additionally to that, it takes an eternity to be able to craft 440er (if you aren't mythic raiding you need over 10+ full hc id's to get the ornaments together). 90% will have a better item on that slot from m+ or war/titan-forged like others have mentioned.
To fix this I would do
1. Make crafted gear BoE again
2. Make Raidmaterials not bop, for example like in Icc and earlier raids.
Maybe you could play with the ilvl then so that not everyone has an instant mythic item, but that would be good. At least imo that is a solution to fix one of the many problems professions have.
(and pls don't turn this post into a discussion ala "if you don't raid mythic why do you need that" or something like that)