Multiple factors:
- Southern Europe is culturally Catholic. Gross oversimplifaction incoming: Catholics: pray hard and get to the heaven. Protestants: work hard and get to the heaven. Obviously nowadays many people are atheistic but the underlying tone is there.
- Climate. It's actually difficult to work hard during summer when most of the day the heat is killing you. Combined with the above explains the lower GDP compared to northern Europe.
- Stronger welfare. You won't starve if you get laid off. You don't need to stress about work that much, you don't have to work overtime to prove sth to your boss. You can clock out at 5pm and go for a drink.
- Walkable cities, public transport. Easy to bump to someone or gather. You can drink alcohol since you don't need to drive. Even smaller towns have cultural life. Small villages have social life revolving around soccer, voluntary firemen and festive celebrations.
- Establishments with reasonable prices. Coffee is super cheap in Italy, Spain or Greece. Even alcohol is cheaper than UK or US. Food is much better. Small low-cost places can have great food while in USA the low-cost is dominated by fast-food chains with exception of ethnic restaurants.
- Stronger family/friend bonds. People move less for work. In USA people hop between states and lose bonds. Even if you move to a different city in Spain, it's easy to hop on a train and spend a weekend with loved ones.
Boils down to "live to work" vs "work to live".
Reporting from central Europe, we are culturally somewhere between north/south (protestant vs catholic morale) and west/east (overall development and other values).
Covid wiped out many restaurants and pubs and people hang out less than before but we still go with friends for a beer often.