I should have added that I worked in prop funds during that period as well, I left finance for a bit to do "pure tech" and then went back to a top N hedge fund until recently (and while there are always silly arguments about these things, N was rarely considered greater than 5) for about 5 years, and while yes everyone was paid nicely there, no one was paid 7 figures for their C++ skills. Quant researchers that were writing C++, different story, but they were paid entirely for their research/alpha generating ability, C++ was just a tool they used to get there. In fact, hearing about their hiring process, it was mostly math questions, I am not even sure there was a big in depth technical portion to their interview loop.
Similarly, there were some AI/ML guys that were rumored to be hauling it in, but this was not for their tech skills- though they were doing mostly python, it was for their AI/ML specific knowledge. As was kind of typical at that place, and most places like it, those guys I think all flamed out and were let go by the time I left. While its not easy to "score a deal" and get promised a very high package for a year or two, its actually much harder in those types of roles to actually keep your seat there. But... if you are actually producing models that generate alpha/profit for the firm, then you are golden.
AI/ML was really just a specific manifestation of a larger trend of if you were on the bleeding edge of a capability that the firm wanted- IE had invented it, or were a very early successful adopter, my firm would have been welling to pay well above typical market to get that. Think along the lines of cloud (2016ish), Kubernetes (2017/18ish), "big data" (2016ish) capability, etc... an alternate route would be to have had successfully engineered change in an org to adopt something like real SRE. Even those types of things, I don't believe anyone was over 7 figures, but maybe? Regardless, the typical path there would be to kind of "burn and churn" those types- IE they build it, maybe its even quite successful, and then thats your niche for the rest of your time there (which is not what most leader types want), or you don't succeed and just get pushed out pretty quick- SRE as a concept was something my previous firm tried several stabs at hiring guys from Google for, but they just never made any real inroads on.