By going there in a browser (and specifically to the mbasic version), you weed out the javascript tracking and bloat, and your adblocker gets to weed out the ads and sponsored content nonsense. As a bonus, there are no auto-playing videos or any of that other junk. That is the problem with using the app (and apps in general): They try very hard to prevent you from blocking ads and sponsored content.

That frees you up to use Facebook for its actual useful function: Handling events and possibly the most genuinely important updates from your friends, without the bloat.

The pared-down user experience in the mbasic version is the entire point. I already filter out everything I don't consider important, and using the mbasic version is another step in the direction of reducing distractions. It also doesn't do the weird re-arranging of discussions and broken infinite scroll that the app does.

It's simply a much easier and less annoying experience.