You can walk into NIPS and find a handful of other researchers that perform at or better in this space.
People in everything have no clue. Nothing to do with tech people being ignorant.
Of course, part of it is being a good negotiator --and I am not the best by far.
Again, it is all about what one side needs vs. what the other side can deliver. You then add a context that includes such things as urgency, uniqueness of the problem to be solved, supply of practitioners with the required expertise as well as other dynamics (does the company need to meet a milestone ASAP?) and you have the makings of doing very well if you are in the right place, at the right time and with adequate negotiating skill.
Of course, if close such deals you have to be able to deliver the goods or you better start thinking about an alternative career.
Of course, I am talking about outliers here, that should be understood. In most of these cases it is, as I said, a right-place, right-time, right-skills circumstance, an alignment of the planets, if you will.
I've seen even crazier stuff. Back during the most heated phase of the internet bubble savvy guys were making outrageous deals. I remember one guy who wanted to charge $500 per hour if he worked from home and $800 if he had to come to the office...to complete a Visual Basic project. No, he was not hired. Wrong place/time/skills.
425k after signing bonus is probably closer to 300-350k base + annual bonus, which feels low for someone in such a distinguished position (close to a typical specialized physician or big tech software engineer with 5-10 years of experience). After finishing my masters degree in machine learning in the mid-2000s, I immediately got job offers higher than my much more talented professors. To me, the real story is that academia has set the compensation bar low for people adding so much value.
Edit: to be clear I know these salaries are high and people in my field are lucky to be making so much. But I also don’t think it’s accurate that people in the field are overpaid, which titles like OP may make it seem.