I'm convinced that if you ask ZM himself, he would also tell you that there's people who exceed him in terms of quality. There's always going to be someone who beats the other one in terms of something. Guys mentioned take forever to deliver a single piece (especially bulgingS) but when they do, visual quality is there.
That comes with drawbacks too though. Dedicating an entire month to one animation that may be too vanilla, unappealing because you may dislike vaginal/anal/oral or whatever or character you don't care about. Of course no variations either (I don't count 4K versions or no watermark ones as actual variants).
Where ZM himself may not have the visual quality of these guys but god damn he has consistency. If he made and rendered animations in Cycles, we wouldn't have variants as it takes forever to do. Current technology is way too limited.
Part of why he's my favorite animator is that over span of 2 years (that's how long ive been following/subbing to him), ZM has never failed to deliver on time, didn't make shitty excuses and always offered fair rewards. Barely anyone does variations on the massive scale like he does, barely anyone as balls to do things he does.
I like him but liking someone doesn't mean you got to be fanatical about it and claim that the person you like is flawless.