Wes Montgomery, Erroll Garner, Django Reinhart and obviously Roland Kirk are probably the most well known that couldn't read at all. There are many, many more jazz musicians that were/are very poor sight readers.
It's definitely true that most jazz musicians can read passably, but my original point was that it's an aural tradition. no one learns to play jazz reading notes off a page. Whereas in western classical music, it's an essential skill.
https://www.amazon.com/Erroll-Garner-One-Hear-Read/dp/B00AZ4...