I feel like with Dublin being more international, there would be more people in their 30's still up for going out a lot etc
This is a little naive- my (extensive) set of SIL/BIL and cousins in law range from early twenties to late thirties, and none of them have a more vibrant social life than those I know in NI or in the U.K.
Most of them are feverishly trying to put money away for a house deposit, or paying an insane amount of rent, so opportunities to go out are limited.
And yes, it’s definitely a much, much more international city, which is amazing, especially compared to anywhere in the north. I worked with a lot of non-nationals, but they understandably formed friendship groups from their own countries of origin.
I always remember one of the Spanish women said that Irish people were really friendly, but it was only surface level. She was finding it really difficult to actual make “proper” friendships with people from here beyond being work colleagues or neighbours etc.
There’s definitely (lots!!! of) plus points to living in Dublin, but I’d just be wary of thinking the grass is greener.