DC was making changes back in the late 60s and early 70s, a welcome development since they honestly hadn’t made many changes since the 1940s. Their comic line was old, stale, and boring, clearly geared to youngsters. Marvel Comics, on the other hand, had made great strides in the 60s and created a vibrant product that appealed to both children and adults.
One of DC’s changes was tweaking Superman a bit. No longer just a reporter for the Daily Planet, he did double duty as a news anchor on TV station WGBS His regular cast of characters was expanded a bit. Oh, and in Superman #233 they got rid of Kryptonite as the weakness of The Man of Steel.