Ireland performed surprisingly well in terms of deaths
It's not clear to me that your explanation of why 'everyone behaved ethically' is correct, not least because not everyone actually did behave ethically: the Golf Society scandal happened very early on! I think a better explanation is gotten by comparing that scandal to the UK's two superficially similar scandals: unlike the Dominic Cummings–Barnard Castle affair, the Golf Society scandal involved very many people organised together, and thus could not just get written off as the poor judgment of a single individual; unlike the Downing Street parties, the Golf Society trip happened very early into the pandemic. I think these two facts helped the scandal put the fear of God into the rest of the country's politicians for the rest of the pandemic (it was clearly institutional, so politicians now had to actively extricate themselves from the attitudes of the Golf Society; and it happened so early there was no time for huge amounts of unethical behaviour to occur beforehand). And I think it's the impact of this particular scandal, rather than anything general about social media, that explains why in general Irish politicians did not get caught in any major scandals after 'Golfgate'.