That's pure sales as in physical product and digital downloads, which nobody buys anymore except old people who don't do streaming. And More Life didn't have a physical release so pure sales cut in half just off that. All that chart tells you is which artists got the oldest fans / the most rabid ones who will purchase albums to show their "dedication". If you look at that chart closely you'll see it's mostly rock or country artists doing the most pure sales (country/Rock fans are old) or Disney soundtracks (parents).