Is Europe sleep-walking out of E.U?

The idea of 'associate EU citizenship'  has been suggested for UK citizens following withdrawal from the E.U.  This looks to be something for purchase, that will allow the same sort of travel/ citizen access as we would currently have. 

Would buying 'associate EU citizenship'  represent good value for money, for someone intending to travel or live somewhere else in Europe even if just on a lark?  Quite unlikely if other current member states start to withdraw themselves, then again who can predict anymore,  Are there any UK nationals currently living in other E.U locations considering this?