While there is no excuse for Kane having lied in his 1965 open letter or for having fudged the truth in his 1989 autobiography, there is some defense of his using his name exclusively when dealing with Batman in publications. Sadly, such a muddled state of recognizing who created who and what was a central feature of the earliest comic superheroes. In a world of pseudonyms, artistic entrepreneurship, and personal studios, one person might well serve as the public name for three or four others. And, one person might even write under a variety of names, thus keeping interest in his work intense rather than overwhelming. Writers trying to make a career in New York City were legion because of the intense competition in the pulps as well as in the slicks (magazines), while good artists were relatively rare. New York, of course, housed innumerable fine artists and an equally uncountable number of commercial artists, but comics demanded artists who not only understood the limits and physics of the human (and extra-human) form, but who could produce a huge quantity of art with relatively acceptable and consistent quality. The same was even more true of editors, who more often than not served as vital figures in the creation and maintenance of publications. During the 1930s, strong editors made, thwarted, and broke writing careers. When Superman appeared, pulp editors were in a strong position, writers in a weak one, and artists in a new and precarious one. While in a relatively good position to capitalize on the new super-hero comics market, pulp publishers, editors, and writers still had to create and then navigate the new market, one that demanded consistency.
— Read on theimaginativeconservative.org/2019/04/dynamic-duo-controversy-over-batmans-creators-bradley-birzer.html