The bit about "Canon, Sony, and Nikon may have replaced Kodak for professionals" was entertainingly silly. AFAICT, Kodak cameras were never used by a significant fraction of professional photographers? (maybe pre-WW2?)
FWIW, Canon, Sony, and Nikon all make sensors as well as cameras (I believe Nikon just tweak Sony's these days, but they were certainly making their own at one point).
Film is a different matter of course.