Let's be honest. A lot of previous partying was made possible by lots and lots and lots of drinking and driving. That of course still goes on today, but nearly at the levels of the past.
When I was in university we thrived on nickel drafts and dive bars.
These days it's $10/cocktail + cover charge.
Get outside a major urban area and it's extremely difficult to find an Uber at the hours when you'd expect to be leaving a party to go home.
Heck, this is true even in some suburbs of New York City.