(Opinions are my own. I know nothing about this program.)

Using StackOverflow's [0] aggregated statistics of pay based on experience + location we can get some rough estimates

Over a 5 to 10 year span as a developer at Google you'd probably touch: Java, Golang, C++, Python, and some part of GCP (or very similar tech). Pay is also different from market location so if we look only at the USA we can look at SF and Manhattan.

5 years:

    - NYC 25% 96k, 50% 126k, 75% 166k
    - SF 25% 113k, 50% 149k, 75% 197k

10 years:

    - NYC 25% 107k, 50% 141k, 75% 186k
    - SF 25% 126k, 50% 166k, 75% 219k

This is also ignoring the FAANG bump that you get from being Xoogler. Also, if you don't get a promotion or are unhappy with your compensation Facebook's levels are an approximate 1:1 mapping to Google and from what I've heard going from Google to Facebook and back to Google is quite common. Some people have joked that there are people that are on a 2 year rotation back and forth.

Some more data can be gleamed from here: https://www.levels.fyi/

500k+ is L6+, while very difficult to obtain, seems doable if you are determined, know your stuff, know how to find the "right" projects, and are also an inspiring leader.

[0] - https://stackoverflow.com/jobs/salary