They are outliers, in that they all are in the very narrow path that I suggested is the only reason I would, personally, pursue an MBA: the MBA allowed them to

They are outliers, in that they all are in the very narrow path that I suggested is the only reason I would, personally, pursue an MBA: the MBA allowed them to jump from banking to Senior Associate roles at elite PE firms (Carlyle, Blackstone, KKR, Apollo). It's by no means necessary, you'll find people at those firms without MBAs - a close friend of mine made the jump directly from banking and is well above the salary range I mentioned, but a top tier MBA helps. It's also worth noting that a majority of compensation from these positions is from the carry on the person's fund (or a blend of all funds, like Blackstone does) and is based on fund performance. This isn't their base or otherwise guaranteed salary.