1. The $100M is a huge number. Maybe there was 1 person, working on large-scale training or finetuning, who had an offer like this, which surely was a high offer even in base (like let's say $1M+), and had a lot of stock and bonus clauses, which over 4+ years could have worked out to a big number. But I don't believe that the average SWE or DE ("staffer") working on the OpenAI ChatGPT UI Javascript would get this offer..
2. One of the comments here says "[Zuck] has mediocre talent". I worked at Facebook ~10 years ago, it was the highest concentration of talent I've ever seen in my life. I'm pretty sure it's still an impressive set of people overall.
Disclaimer: I don't work in the LLM space, not even in the US tech space anymore.