Does anyone remember the private message feature on YouTube

Long time ago now, I think they withdrew it in 2013 possibly? But it was a great feature on YouTube, as I used to private message my subscribers or people I subscribed to and have good chats with them-get to know more about them..

It would be great if they brought that back… anyone know why they discontinued that feature?

I just think it made YouTube more social and provided the ability to connect to your subscribers or those who you were subscribed to.