Puzzled because I use Messenger web version all the time on the laptop. Works pretty normally. I don't use Facebook usually. Maybe if they detect a phone they refuse?
Usually they only break the mobile websites. They know they won't get people to install programs on their computers for "online things". Not least lots of people don't have admin rights in their computers, but also people are used to accessing "online things" via browsers on computers rather than an app per website.
But, they've managed to make "phones use apps, not browsers" a social norm that enough people accept tacitly, perhaps because near enough everyone has the ability to install apps on their own phones.
