What you consider an "inefficiency" is part of a lifestyle in big parts of Europe. Going out to eat isn't just considered "calorie intake" that needs to be "as quick and efficient as possible", it's considered leisure and social time, especially in the southern parts of Europe like Greece, Italy or Spain.

It's also very seldom that people really manage to just drink one bottle of wine in 3 hours, usually it's bigger groups and they tend to drink a lot once they finished eating. Depending on how the restaurant prices their drinks the "3 hour drinking group" can end up making way more money for the restaurant than trying to shove 3 parties of "Just eat something with a small soda", into the same timeframe.