The optimal amount of Social-Media Usage for any normal human-being can be delegated to a simple rule of thumb, a practical scheme that you can participate in quite easily:

A healthy dose of social media, email, and SMS usage occurs when you use them primarily for your own purpose.

Whether it's because you wanna contact a friend for something. Or You just wanna grab that 2FA code from your email. That's probably enough for

1. Keeping your sanity.
2. Noticing any rare important issue.

Considering that rule of thumb, it looks like the optimal amount of most things will be dropped into 0. Because you are not using them out of your boredom.

And that's fine.