Well, after "Gozu" he still had something to say (Zebraman, Yatterman, Izo, and his remake of Django all came afterwards), but I think he lost the spirit that made his earlier work so distinctive, especially films like Visitor q, The happiness of the Katakuris, Dead or Alive series, or Ichi that came out around the turn of the millennium..
As for Tsukamoto, I think he suffered from the transition to digital, but up until "Vital" he was still making great stuff. On the other hand, I found Kotoko terribly irritating, both in terms of story photography.
Although "Killing" was good and pretty solid.
I'm currently going through Ben Wheatley's movies. I don't think he's ever made something truly great, but I like his anarchic spirit, especially when he works with medium/low budget productions. Some of his films are far from perfect (In the Earth, just to mention one), but at least you can say he has a vision.
On the other hand, his more mainstream work is pretty boring. Meg 2 was terrible, while Rebecca (the Alfred Hitchcock remake he directed for Netflix) had a few good ideas, but it could have been shot by a random director. Stilistically is pretty anonymous .