I think asking if people "take him seriously" suggests that his career was more ambitious than it ever was (unless you count the Jeff Beck group's ambitions). IMHO his classic early stuff is pretty good, but I don't know the individual albums well. I have zero interest in anything after the mid-70s. If you count the Jeff Beck Group, The Faces, and the stuff he did solo while in The Faces (which is mostly backed by the other band members anyway), that's actually 11 albums in six years. His career would seem less shitty if he'd started off by releasing the same amount of music of the same quality more slowly.