The drinking started much earlier. Typically you'd drink at home first so that you were already drunk on cheap liquor. Sure, if you had a place nearby that had specials that could compete with the cost of drinking at home, you might opt for that instead, but there is no material difference found in that. What is key here is that people did everything they could to keep the cost down, limiting the high cost experience associated with going out to just a couple of hours before everything closed down.
The "YOLO youth" of today don't care. Some researchers have suggested that because they feel they have no future they have no qualms about spending today, but whatever the exact mechanics of are it is clear that they aren't trying to pinch pennies like previous generations did. They are almost certainly spending 5x more, but that is buying them an entirely different night out as compared to what people were accustomed to in the past. The same night out isn't 5x more expensive. Not in any way, shape, or form.
Back in my day you didn't even leave home for a night out before 11PM. You couldn't spend that much even if you tried before everything was closed and there was nowhere left to spend. Young people today, on the other hand, are favouring starting the night out in the early evening, even the afternoon.
A night out may cost 5x more, but the same night out doesn't.