I happen to be reading "The Millionaire Next Door" [1], and this has some truth to it (statistical excerpts [2]). Most "working class" Millionaires own a small business and are very frugal, continuing to live below their means after obtaining their wealth. Frugality alone will not help you attain the quoted wealth level, but it is a component (along with a healthy income and/or equity/asset ownership).

With reference to "common jobs", that would be limited to high income professions, such as doctors and attorneys.

[1] https://smile.amazon.com/Millionaire-Next-Door-Surprising-Am...

[2] https://www.washingtonpost.com/wp-srv/style/longterm/books/c...