This is fairly coming financial technology except less base and more bonus. I've seen plenty of $500-800k base with 4x bonus (and more especially if you are close to the money or on the front desk). I think it is very healthy. It creates tiers in the profession because some developers are that much better. Being good glueing together frameworks isn't going to command that salary.
In the UK at least, you're talking about the top couple of dozen in any of the major investment banks. Only a couple of hundred in any given bank make more than a million total comp.
https://news.efinancialcareers.com/uk-en/159654/everything-y...