Zuckerberg got lucky and then executed brilliantly, transitioned from nerd hacker to CEO amazingly well. He deserves a lot of credit for that.
Since then, Facebook have innovated very little. Zuckerberg recognised this, and bought Instagram and Whatsapp in lieu of building an innovative company. The latter is clearly really difficult to do.
Without a stream of new ideas and products (unlike, say, Apple) Facebook double-downed on maximising revenue growth from their core advertising business. This led to all the scandals and disasters they have brought us, including destabilising societies.
Inevitably, this led to the core product becoming less attractive, and people were also turned off by the negative press. Zuckerberg's rigid control of the company has led to him being a lightening rod for the backlash against big tech and especially adtech. His media skills are awful, so insisting on control and making himself a figurehead has further damaged the business.
Zuckerberg knows the only way out is another home run. He's a super smart and prescient thinker, so he can see VR is a good play. It looks like the timeline for VR won't be short enough to save FB, but even if it were arriving soon enough he must know that FB probably isn't capable of delivering a truly new thing.
This then marks the beginning of the end for the company, as it continues to bring in revenue from Instagram and monetises Whatsapp. Its sheer size means decline is going to take decades.
I wouldn't be surprised if Zuckerberg leaves in the next few years, before the failure of Meta strategy becomes apparent.
What they _should_ have done is debatable, but developing some sense of ethics might have helped. I think they could have focused on building Whatsapp into a payments (etc) app, which would have created an enduring product, and then used the time that bought them to rebuild the company.
Microsoft are showing that it can be done, but I wonder if Facebook has the capacity to do great things. Perhaps the lesson from MS is that only a new leader can rescue such a mired company.