I just wonder: are Early Adopters rich?
We know AA, author of "Mastering Bitcoin" was once attacked because he did not made any fortune having BTC from early years, then people donated some BTC and he collected around 100BTC.
Hal F's wife sued "I am Satoshi guy" and they were talking about $ 3-digit mln, so they are not kind of people who wait every month for their wage.
What about others? Bitcoin Core developers? Forum admins or well-known old users? Are they crazy rich living in their own castles or did they lost their coins, sold for $10 because of mortgage loan or student's debt and today they must work 7-15 every day?
Some of them that sees btc as an asset yes because they buy and hodl them up until now but for those who only adopt btc as a currency for daily use then no they haven't made a fortune through it. Is that "mastering bitcoin" a book? And it is digital and being handed freely?
What a nice guy the author then but if this happens to other authors, they will be selling their books because they have use their time and effort to create it, most especially if it's a physical one since you need some materials. Luckily the author that we are talking about still got donations. 100 btc is huge especially if that kept until today. That was still considered as a wealth or fortune.