Have a look at the stock chart for TQQQ.
https://finance.yahoo.com/chart/TQQQ
10 years ago the stock was roughly $1.80 (split adjusted).
Now it has reached $175.
175/1.8 = ~97.2 increase in value
$10,000 * 97.2 = $972,222
So not quite 2M, but still a good return. However, that is 10 years, but 100k/yr annualized isn’t bad.
Bear in mind that cherry-picking stocks (e.g. if only I had invested in google at the beginning) is easy to do in hindsight, and not all leveraged ETFs take off.