Frankly, the "sweet spot" is somewhere between artistic self-confidence and the needs of marketing. He publicly stated that Kill Uncle was better than Viva Hate and that Maladjusted was the best of him. In either case, anyone with a pair of reasonably functioning eyes, one working ear and half a brain would tell you otherwise.
Well that's the problem. He is
Permanently a prisoner of the present, and of the future. His current batch of songs, is always, in his estimation, the best he's ever written, until he writes some more and the past becomes prologue.
I think, in his mind, he genuinely believes he has always been on an artistically forward trajectory. To a certain extent this is understandable,.I think the artist must believe that, or at least proceed as if that were rue,: because if it weren't the case that his best has yet to come (always), what is the point of even trying to release new music?
Of course, as you rightly point out, most of us can see that those proclamations aren't true, that the best isn't necessarily yet to come, and may have even already been accomplished at some point in this discography.
I think there is a reasonable middle ground to be had between genuine pride in your current unreleased material, while also acknowledging how your songwriting has changed, that other people might reasonably disagree with your constant trumpeting of the present and the future of your artistic output, and to maintain some level of self-awareness.
I would be much more open to entertaining the veracity of his enthusiasm, if for example, he ever talked about the production process talked his producers or co-writers, or whatever brought to the present project. What about what they presented in demos or in the studio inspired him, or vice versa?
Of course, this is the same reason that he doesn't have a record deal at the moment. If he were willing to work with capital, on the anonymous terms the terms of the Miley vocal, or its removal or accept a more modest deal from a smaller company, without the prestige, he would probably have three new albums out by now and probably have remasters of all of the 2000's era stuff