I'm embarrassed to say how many I had ðŸ¤... but now I'm down to 6. Thing is, I have 2 relays that I run that store my info, but don't allow anyone but myself and my family to post content to... so I kept a couple extra public ones. The whole relay thing is confusing.
Discussion
Public OutBox and Public Inbox are for your followers. If they can't use those relays, there is no point on keeping them there.
You can use the Private Home, Local Relays or the general list to keep things that only you can access.