Why does Debian not include POSIX-specified commands like bc and ed by default?

[POSIX.1-2001](https://pubs.opengroup.org/onlinepubs/009695399/) [Utilities](https://pubs.opengroup.org/onlinepubs/009695399/idx/utilities.html) and [POSIX.1-2008](https://pubs.opengroup.org/onlinepubs/9699919799/) [Utilities](https://pubs.opengroup.org/onlinepubs/9699919799/idx/utilities.html) both list the commands bc and ed to be part of POSIX. Yet, in a brand new Debian installation (version 10 for example), these commands are missing by default:

$ bc
bash: bc: command not found
$ ed
bash: ed: command not found

Why does Debian not include these commands by default? Of course, I can install them with and I did that.

apt-get install bc ed

The bc binary is only 87K in size. The entire package including the man page and documentation is only 209K in size. Similarly the ed binary is only 55K in size. The entire package is only 93K in size. What good reason is there not to include these tiny packages even though they are specified in POSIX?