I agree on the aging thing, although that only became obvious to me in the final third or so, when the old age scenes seemed too long - until I figured that getting there had been the point all along.I enjoyed The Irishman better on a second viewing once I understood that it's a movie about getting old/old age, and that this is the entire point of casting really old men in the leading roles (at least that's my interpretation).
My issue with The Irishman is rather that Scorsese landed about halfway between a miniseries and a film. I think he should have either cut out some of the relatively underdeveloped storylines completely (a couple of which I found a little jarring in their briefness) and make a shorter and more focused film that treats fewer themes better; or expand upon those stories/themes properly as well and make a miniseries of some five or six episodes.
And also entertaining often in the 'haha, the guy in the trunk isn't dead yet' or 'haha, he just shot the guy in the foot out of nowhere' sense. I liked that as a teenager and 20s (see also Pulp Fiction), but I'm mostly turned off by it now.Goodfellas is just extremely entertaining, but yeah it doesn't have much interesting to say about anything.
Casino is a great story, but I find De Niro so dour and wooden in it, one of his weakest roles before he gave up on serious acting completely. But in fairness, the character he portrayed, Lefty Rosenthal, wasn't particularly charismatic or fun it seems:
I totally have to rewatch it after what you and @Sweet Square have been saying about it. I don't remember it too fondly, but then I don't actually remember any specifics about it. The main thing that comes to mind is De Niro bashing someone's head in with a baseball bat, which is actually from The Untouchables! I see I have it on DVD even, let's see when I can make the time.