Akonadi is a pig. Nearly 20 processes, each one using 20-150MB resident set (20-40MB unique set), multiplied by the number of users logged in. And then there's the other stuff it keeps resident, like mysqld.

That might be okay if I was getting something important from it, but I'm not. It provides zero value to me. It's just wasting RAM that I would rather use for other things.

Unfortunately, it's part of the Plasma dependency chain on my distro, so removing it would be problematic. When I find the time, I may build a custom metapackage to allow me to get rid of it without taking most of KDE with it.