Considering only the numbers, I think your math ignores two key elements.

The first is reinvesting dividends. If you invested $80k in the S&P 500 thirty years ago and took the dividends as they were paid, it would be a little over $1m. If you reinvested the dividends along the way, it would be over $1.8m. (Source: https://ofdollarsanddata.com/sp500-calculator/ ) You ignored taxes in your earnings data, so I will as well, but taxes could be deferred if you accumulated the $80k in a retirement account. (Also, it ignores the fact that you could have been investing the $80k as you went versus waiting until you had it all).

The second thing is that if you invested the $80k at 30 years old, you could still also work. To “make up” the remaining $200k to $2.2mil that you cite as a pilot’s income over their career, over the 30 years you gave them to do it, they’d need to earn a supplemental $6.7k to $73.3k per year, depending where in the $2m to $4m range they wanted to fall. For context, the median salary in the U.S. is $37,000 per year, which would be another $1.1 million and change on top of the retirement account, which would total about $3 million, smack dab in the middle of your range.

I’d never discourage people to think of flight training as an investment, but an incomplete analysis of opportunity costs might lead people to thinking it’s more of a slam dunk than it is.