Syd I guess Virtual Reality is the great filter in a sense. They are all out there, but plugging into your own personal fantasy kingdom is way too enticing and every intelligent species goes that route before developing interstellar travel.
Funny you should say that.
We went to collect my husband from Heathrow on the train so we essentially travelled right through London.
What struck me was the average age of everyone we saw. I mentioned it to my husband..."Where are all the young people??!! Is it me or does everyone look so old!! I thought as you age you're supposed to feel outnumbered by the young!!"
My husband said "oh they're here all right. They just never leave home." (i.e. They're all plugged in/online/gaming etc etc)