It seems this "world view" of Champagne drinking in this thread is limited to the UK. I live in France and it's quite a different story. People drink Champagne, or a local variant, as an aperitif. And usually only one glass, unless you need to down two to empty the bottle. Or maybe more if it is about a big celebration.

In Burgundy, and some other regions, we don't even drink actual Champagne, fancy or otherwise. We drink crémant de Bourgogne which tastes as good as normal Champagne for about €7 per bottle. So it isn't at all about showing off.