Not wanting to diss Ed Sheeran as lots of people probably like him, but over the past few days saw lots of bands better suited and just better, to headline the main stage
I don't think you can really put him anywhere else. Like his music or loathe it, he's one of the biggest musicians in the world at the peak of his popularity. 9 songs from his most recent album reached the top 10 at the same time, every single one got into the top 20. The big one was number 1 for about 4 months. Clearly a headline act on the main stage.