The problem with K&R is that it stops at C89, while C99 almost feels like a new and much "friendlier" language (mainly because of compound literals and designated initialization).
K&R 2nd Edition is still a very good read of course, but mainly for all the little interesting details that are not directly related to the C syntax, but there really should have been a K&R 3rd Edition when C99 came around.
From ANSI C to C99 there isn't many changes. Just read K&R C 2nd ed and then the book on Modern C which can be understood in a literal afternoon after doing the K&R one.
Those standards barely change anything. You could discuss the “new features” over the last 30 years in about 10 pages after learning the fundamentals. (10 pages may be high.)
Some of the best programming books date from that era. Programming hasn’t really changed all that much in decades. New tools and languages, sure. Mostly retreads or derivatives.