(I am American - or USA-ian or whatever you want to call it)
I was surprised to find the similarities, not just due to 'movies' representing Irish accent distinctly (I don't think I've seen many films featuring Irish) but based on Irish people I've met whose accent was more distinct from my point of view.
About the videos, I would say the beginning part of the guy from Northern Ireland seemed more distinct, while the latter did sound closer to American. The girl sounded close to American consistently thru the video... but the thing is, she explicitly says other Irish people don't think she has an Irish accent, so I don't really think that is good example.
Here are links suggested when I watched those videos, which have more distinct accent vs American:
Guy portraying multiple Irish accents https://www.youtube.com/watch?v=hIeks_F3yOE
The latter may be over the top because he's portraying stereotypes, but Irish I have met did have accents on the continuum of those and the girl I linked. Incidentally, while not super engaged with Irish culture, I always thought it was the nicest sounding accent(s) amongst English accents. The more American-sounding accents the OP posted would not really qualify as especially notable if I had to rate them. I don't know if there is trend for more American-ized pronunciation with modern film/TV and so on familiarizing Irish to American accent?