What is the purpose of the command-line options "-ANe" for MySQL?
The biggest reason was already stated by Vérace, but I wanted to add to it

When a database instance has lots of tables and lots of columns, the information_schema has to inspected in memory. This can be a cause for alarm. Why ?

Back in April 2014, I wrote the answer to Do Inactive MySQL Databases Consume Memory? and Adding new tables -- memory usage increases.

I have seen MySQL instances with 800+ databases with each database containing 162 tables.

Imagine loading metadata for the DB you connect to. Lots of needless prep work for the beginning of a DB Connection's LifeCycle along with allocating memory for a local copy of that metadata in addition to per-session buffers (See my post How costly is opening and closing of a DB connection?)

This is the biggest reason why I use -A to connect to do little things.