Bob Hope had said that when he started he relied on a “gag rag.” He would use the jokes from those. He said he knew early on that he needed a stash of material and started buying lines as soon as he could afford it. Eventually, he relied mainly on his writers, although he had a great sense for a good joke. Phyllis Diller also relied heavily on writers and employed housewives across the country for her material. There comes a point where the comedian is too busy doing other things to really focus on generating new material themselves and turns that over to writers…thank goodness.