This doesn't match my experience at all, starting from the beginning. Many go to cafes alone to read, work, study etc. Seating set up for this, including small tables and bars. That's one of their biggest draws. With large fluctuations, I estimate ~30%.

I suspect this depends on the location, given this contrast. It seems the Author might be from Delaware, USA? I haven't been to any coffee shops there. Maybe this is an exception? Of interest, it does not match my experience in coffee shops elsewhere on the East Coast (Va, NC, Mass for example). Not my experience in various European countries as well.