I think the original album and Demon Days have a lot of continuity in terms of sound. You can trace from Tomorrow Comes Today to something like November Has Come to Rhinestone Eyes pretty easily. It gets harder for Plastic Beach, though, and Humanz, at least so far, is even more removed. The most 'Gorillaz' track is probably something like Andromeda, but most feel quite thematically different.
Not worse, mind, at least for me. My music tastes are pretty varied and I really like Humanz. But I can understand some people who might have especially treasured the lineage of Gorillaz and Demon Days being upset, especially as there's almost nothing else that caters to that niche.