Genuinely? Damon Albarn.
I used to admire his creativity and his gift to will unconventional music into existence. (Mostly with Gorillaz, examples being DARE, Bill Murray, which by extension includes the majority of D-Sides, DoYaThing, etc., though Think Tank is another good example.)
I would say he was at his best between 1997 and 2007, with his work becoming increasingly worse sometime in 2014, but it varies depending on the project. With Blur? 2010. With Gorillaz? 2017, although 2018 solidified it.
Now he has two modes: shitty synth pop with a bassline that sounds like a duck quacking or shitty piano ballads that all sound the same with no variety. (The latter applies to both his solo material and with Blur, specifically their most recent release, The Ballad of Darren.)
I'm hoping The Mountain will be a good release, but I doubt it. I mean, ffs, even his song titles are generic now. "The Ballad", "The Narcissist", "The Heights", "The Rabbi", "The Swan", "The Happy Dictator", and now fucking "The Mountain". I'm sick of it.