Why does Bezos always feel like he needs to be everything for everyone. He is almost as bad at focusing on core businesses and strengths as Zuckerberg.
Mega constellations are a new focus, obviously inspired by Starlink, but it's entirely rational given the context of Bezos already owning a rocket company. Operating a fleet of communication satellites has been proven as a working strategy for paying for a lot of rocket launches. At this point, any rocket company that doesn't have similar plans in the works is asking to be out of business.
Zuck has one website that's been a has-been enshittified hellscape for going on almost 10 years now, another he very well might be forced to sell, and a pivot to a "metaverse" that's nothing but one big bonfire of cash. Meta may be R&Ding the shit out of VR/AR, but there's no guarantee they're going to be able to cash in.