For every person at Snap, Adobe, FAANG, etc making ~200k starting, you have another SWE at Goldman making 120k and another at HP making 80k. i.e. you are comparing the top of the distribution with the middle, and further undiscounting the CoL associated with living in SV.
I don't think he needed to MBA, but if it got him that job, then it may have been worth it. Not everyone wants to be an SWE or data scientist, and its not the only lucrative career.
I know and work with enough of the types of people you speak of to understand what it takes - that's all I'll say.