When software requires you to read manual, then it is strong hint that it has poor UI UX
Like, you dont read web browser manual to use it, even when using advanced features like debugger or dev console (advanced in compare to non-computer person)
Make is a power tool and power tools require effort to fully understand and master (though the base case in Make is surprisingly simple). It also has great documentation (which is something newer generations either don't appreciate or don't care about).
The manual has everything and is not long. It is actually very concise, but with the caveat that within each page you have to read everything. Every sentence of the manual has important information.
Started as a simple idea
Required more sophistication
Became something no one person really understands