He headlined BST just before the pandemic. That's pretty relevant to his status as a UK festival headliner.
Let me check with SZA whether she reckons Spotify streaming figures are the biggest factor in headlining the Pyramid
I'm not sure quoting gigs he did nearly 30 years ago is relevant.
I'd argue that Spotify streaming figures are a more relevant metric in this day and age. Cat Stevens dwarves Neil Young in that regard.