I mean, the same can be said for consulting salaries, HFT salaries, hedge fund salaries, etc., which similar to software engineering only require a bachelor's and have a similarly grueling interview process.

Why would this equalize? As long as software companies make huge profits and have growth capability which the top ones clearly do, what change would make this happen?

Some software companies are making huge profits today. Many software jobs are at companies making returns comparable to other engineering job profits. There's also a supply side. If the market is flooded with a lot of people in it mostly for the money, salaries will supposedly shrink.