TBH you don't really need to categorize content to see that there's a big gap in difficulty between stuff like normal/alliance raids and extreme trials/early savage floors that's not present anywhere else in the game. That gap used to be bridged by Bozja and could have been filled by Criterion if they didn't skip straight to savage difficulty for w/e reason.
This is also such an insane take to me, it's like saying you can't enjoy playing Mario anymore after beating Super Meat Boy. I always had fun doing CE's unless it was the 50th time doing so, and having cleared TOP 10x never changed that opinion, if anything I appreciate it more considering how badly designed that fight was. But I digress, to each their own after all.You cited Bozja/Eureka as closest to Midcore, but for someone like me, they sit wholly in the casual range without "close to" being even a consideration. Every CE is brain dead easy to figure out, Dal/Castrum are both slow motion easy fights, literally the only piece of contents in either of them that i would define as 'midcore' would be Duels, BA & DRS (which are all plagued with accessibility and ease of access issues).