It's unlikely he sees or even perceives what he's doing as a grind, but rather something akin to an exciting and engrossing chase or puzzle. If my mental model of these kind of Silicon Valley types is correct, neither is he likely to be in it for the money, at least not at the narrative self level. He most likely was "feelin' the AGI", in Ilya Sutskever's immortal words. I.e. feeling like this might be a once-in-a-million-years opportunity to birth a new species, if not a deity even.