Why does this appear to be "random" to you? What is your definition of "random"?
Have you tried "putting on a Mozilla hat" and thinking about their priorities and goals? If you do, I think you'll likely see some connections. After you do this for a few minutes, I'm interested if perhaps you can see another point of view.
Also reminds me that their mobile division seems painfully understaffed.[1] After using Firefox Mobile for a year there still isn't even a way to search your history, along with a dozen other pain points I put up with daily. And the most painful issues I bring up are either closed or never get addressed for months, or ever. It makes Chromium-based browsers even more tempting to me, and in cases I've had no choice but to use them for things like caching bugs with stale development assets, but Chrome is really all there's left if we lose Firefox.
I really, really hope that they do not sink the current iteration of mobile Firefox. When I see resources being used on projects like these, I just wish the more pressing issues were prioritized. Firefox is the face of Mozilla.
I sometimes have the same reaction when learning the number of people employed for what I would have otherwise thought to be some meager thing. Then I get reminded about the folks over in external/internal support; marketing; design; IT/infrastructure; legal; compliance; etc.
Here's Mozilla's listing:
That’s the bulk of the team that got layed off, by the way. I think there was some last-ditch effort that was able to preserve the MDN efforts.