I wouldn't be surprised if somebody with a user name ending in eleven showed up saying "charge more", but I believe that rallying cry has already pretty thoroughly saturated HN and the bootstrapper world in general.
So much so, that most of us are blind to what actually does differentiate Adam and leads to his success.
A more under-valued takeaway than "charge more" would be "the power of free". Adam built a massive following by giving devs what they wanted for free while contracting. This ranged from sharing countless useful tips on Twitter to blogging and then later podcasting.
During his excellent interview with csallen on IH[1], he described this practice of helping people for free as a "spring" that he was pushing down on. When he finally sold something, that stored commercial energy was released!
Each cycle he's pressed the spring down harder and longer.
His earlier courses came together relatively quickly. His design book was started on the back of a longer free campaign of tidbits on his blog and twitter. This time, he started by building Tailwind CSS into a top-notch open source library with extraordinary growth for multiple years before he monetized it with Tailwind UI.
1) It was csallen's helpful post on IH that sparked me into disagreement to write this one! See: https://www.indiehackers.com/post/adam-wathan-just-made-500k...