I think the 500k TC posts are usually talking about the massive stock appreciation that the FAANGs have gone through.

For example on Feb 4, 2019 Amazon was trading at 1623. By Feb 4, 2022 stock is trading at 3,112. This multiplies the value of any TC in years 3 and 4 by a significant sum (given the 5/15/40/40 vest) due to the near doubling of stock value over 3 years.