How many social media channels can one person manage well?

Posted by Inspiretothrive under Social Media
From https://medium.com 487 days ago

I’ve read that the average person has 7 social media channels. I was surprised at that number as I’ve always remembered reading that one person could only manage 3 social media channels well.
(I’m not talking about having a social media channel where no update has been done in years.)
That number of course is without using any social media scheduling or other tools to manage the social media. There are at least 65+ social networking sites worldwide today.
Yesterday I was on a Twitter chat —#BizapalozzaChat and many peeps were talking about spending 20–25 minutes on LinkedIn everyday. This got me to thinking: Is 30 minutes enough on each channel and if you have 7 channels that would be 210 minutes or 3.5 hours per day!