Yis are all assuming the only way to drink alcohol is the Oirish way - start at 9pm and keep going until you drink yourself unconscious or you get knocked out during the post-pub fight outside the chipper. If you go to my local mid-week, you're more likely to see people eating their dinner and a glass of wine for €15 rather than 5 lads knocking back pints at the bar.
Little venues (above a regular pub maybe) might sprout up that support niche activities. Maybe a sports club that watches live American sports? Or a cinema club that severs dinner before/after the movie with an invited speaker afterwards. Or maybe a 'come-down'/chill-out venue. Or maybe a venue for night-workers only?
There's a tea cafe in a basement along Ormond Quay and it's been going for 10 years or more. I only went once (against my will) and i thought it was stupid. But it's still there after 10 years so there is a market for it.
Maybe the young folk might visit 3 venues in one night? 1. (9-midnight) The pub downing Guinness whilst talking sport. 2. (midnight - 3am) A traditional nightclub with more drugs and less talk. 3. (3-6am) A chill-out serving small amounts of alcohol, more fancy drinks and casual buffet-type food.
Who knows what we pop up once people are given a chance to try out new ideas!
Leeson Street survived because people didn't want to go home at three.
Gigs place on South Richmond Street was absolutely hopping for "Breakfast" after three AM. The Manhattan on Harcourt Road was open until the sun came up.
My favourite haunt was Eliza Blues on the quays in Temple Bar. You could leave a club, and knock on the shutters of Eliza's - which was a restaurant until midnight - then a speakeasy rave afterward.
Lots of scope for late -night venues.
The Gaiety had Mambo & Velure until 05.00 - absolutely brilliant, with club music, live Jazz and a silent movie in the theatre to chill...deadly.