Not all bash builtin commands have their man page
Having man pages for bash builtin commands is convenient.
man echo provides the man page for the bash command 'echo'.
Some/most builtin commands do not have their own man page.
man read give man 2 read, which is about a c++ library. There is no man page for man 1 read (bash's read).
The official bash documentation is unwieldy.
Currently, my info pages are broken: #5475: The Info node shell builtin commands in Info file /usr/share/info/bash.info does not exist.