Blueprint is meant for desktop applications. For example, Electron apps. You'll notice Blueprint tries to give that desktop app feel, versus Antd, which does not.
I believe they meant desktop-feel as opposed to mobile first (mostly because some consider Material to be a mobile-first decision). Additional Note: Blueprint doesn't go out of it's way to degrade nicely for mobile screen sizes for most components and doesn't provide the grid layout or progressive embeds typically associated with mobile-friendly UI libraries.
