Earlier quoted context omitted.
That is such a nerdy perspective, totally stuck in the filter bubble. I don’t think that explains the difference at all. I think it’s about convenience. People don’t want to use apps for the diverse things they do on the web all the time. Apps may be convenient if you use them frequently (and then only marginally, especially with improving speeds and more people paying attention to making websites usable on phones),…
poeple especially don't need apps of 150mb+ each, and premium phones come with limited storage forcing costly upgrades on top of an hefty price. the only competitive advantage for apps is push notifications, and the sooner browsers and phones can build that into a standard the better (including opening the right page when clicking on a specific service notification)
Looking at the ridiculous number of permissions different apps would require to run on my (Android) phone, using mobile site of the most of the services seems safer choice. Android 6.0 may change this with switchable permissions, tho.