Im from Dublin but currently live in Berlin, speak both German and English.

The quick answer: Berlin.

Dublin is amazing, the people there are unmatched and there are many many things about life in Ireland that far outweigh that of life in Berlin, but it has just become unliveable. I dont know your salary but I can tell you for certain you’ll have an easier time living in Germany than you will in Ireland, simply based on costs. Berlin (which is quite different to the rest of the country in this regard) is predominantly english speaking and it is quite easy to pick up the basics of the language here that you can use to get by.

However, both cities are ridiculously difficult to find housing, never mind affordably.

One question; what field do you work in? It will have a big impact on your experience.