What annoys me is that AppCenter takes up so much space in their blog posts and sponsoring campaigns, because I feel it's the worst of their apps. The navigation model never made sense to me (why is search disabled when I'm on "Installed"?). It also doesn't look good, because there are way more tiny utility apps than there are good icon designers, and often the icons are just shown on a giant, colored rectangle because apps have no banner images.
I wish they'd do it more "magazine-like" as Apple does, just with more unsplash images instead of Apple's terrible Corporate Memphis illustrations.