Just consider it flat out: Pick something you did three years ago. Let's say it took you a day, or a week, or a a good chunk of a month, off and on. With no followup work after that, what's a "reasonable" rate of return for that effort?
I make a good hourly rate, but at the end of each hour, my earning from that hour is done, and none of my hours have every billed at $149k.
You can make that argument about any kind of job. Is the CEO who makes $10M a year really worth 100x the marketer who makes $100k a year?
It's all in what you value, and who has the most leverage to get more money for whatever value they may provide. You may not think it's fair that the record company made some large multiplier of what the artist made, but that's just how the business works. If you want to change it by cutting out the record company, it's a lot easier to do that than it was 20 years ago, so I'd say the situation for artists in that regard is better, not worse.
In the end it absolutely does not matter what anyone thinks is "fair". Absent some form of regulation, people are going to extract as much wealth as they can out of a series of transactions, and some people are going to be more advantaged at doing so than others, whether because of talent or for structural reasons.
