I, like most of us I imagine, run into many more people (myself included) who sing/play songs than people who write them. Songwriting thus appears to be a rarer skill than singing/playing, and that can make it seem to be a greater gift. But I must say, I seldom run into a really good "home-grown" song, and I have more appreciation for a well-rendered cover than for an original clunker.
So I don't see songwriting, in and of itself, as a necessarily greater gift than singing/playing. Yet while any number of folks can do a commendable job of performing others' work, presumably only one individual could have written that gem of a song that is widely admired. That is a rare and noble talent.