Is this really true? Mobile device users are all mostly forced to use apps rather than the browser for most stuff, and people on desktop PCs/laptops are probably either using them for gaming (all desktop apps), or work where a lot of stuff is desktop apps.

Sure regular consumer stuff like social media is webapps (if they're not mobile only), and if you're interacting with like salesforce or a customer support tracker or an issue tracker or something you're likely using a webapp, but the move to mobile devices for most consumer stuff means that people still using PCs are largely power users.