the peak of his career/craft
Career and craft are two different things.
That article said 1981 was "the height of his literary success," but I think the writer just needed to say something about 1981 and he didn't know anything so he threw that in. In 1987
Barfly,
Crazy Love, and
The Charles Bukowski Tapes all came out. I don't think he was ever any more
high profile than he was at that time. Does being high profile make you a success? Movies aren't "literary success," but most people probably think having your book turned into a movie is the height of wonderfulness.
The height of his literary success, financially, was probably, as he predicted, after he died. You now, whatever literary success is. Bukowski probably felt
literary success when he pulled the first copies of
Flower, Fist and Bestial Wail out of the box in 1960.
"Success" is all about what the rest of the world sees in you anyway, not what you see in yourself.