Solid film but there are glaring problems

Rating: 6/10 (15 October 2019)

Okay, when I first heard that there was going to be a Joker origin story film I just didn't want anything to do with it. I just feel as though with his ideology in the comics, the cartoon, The Dark Knight movie and other stuff that less is more to explain why he is the way he is. Then the first trailer hit and my expectations changed again, it changed them from "kind of meh" to completely sold on the idea. So I sat down and watched it and... it's GOOD but things get a bit complicated.
I'll skip over the plot because I'd like to summarize the benefits and disadvantages this has as a film rather than go over the plot to a movie you've either seen or want to see (I mean I assume that's why readers are here). I'll start with the compliments - Joaquin Phoenix as Arthur Fleck is a good and nuanced performance with the steady deterioration from mentally ill but harmless guy that wants to make people laugh, take care of his mother and make ends meet to a psychopathic killing machine is well done, and to address the controversy - I really struggle to see how anyone can interpret this as anything other than sympathetic villain, as in you can see why he does what he does but you don't agree with it.
I'd also say the acting from the other main players, the cinematography, the way it flawlessly blends fantasy in with reality so any 2 people can walk out of this with different opinions of what actually happens in this movie all works well as is the rather nihilistic nature of the plot - where things escalate over essentially nothing does fit in with the idea that this is an origin story to a villain that does horrible things because he thinks it's funny.
So what are my problems? Well I don't think they got the character of The Joker down for one thing - Arthur Fleck slips in and out of fantasy stuff like dates and appearances on his favourite comedy show. I'm going to say it - The Joker's blend of crazy ISN'T the failure to distinguish between fantasy and reality - it's that his ideology is so warped that all the murder, mayhem and violence - he thinks the pain he causes has a funny side to all of it. He also creates complex and intricate plans to all of this - he is essentially as smart or smarter than Batman, a self proclaimed "World's Greatest Detective" but also his opposite. Arthur Fleck seems more like a character The Joker of other media would use(for his plan), chew up and spit out like he frequently does with Harley Quinn.
Well I don't think the whole "That's not The Joker" is a bad thing, just when you call your movie Joker - it really needs to be said. My other complaint is a very simple one - this story does have themes in it. Mental illness, not treating it properly from the government, income inequality, failed dreams, failed job prospects, failed dating prospects, horrible blood relatives and does absolutely nothing with it. The final scene cuts back to Fleck in a mental hospital - meaning it's big statement on this is "These exist, do with that information what you will". Even in media that tries the "all is for nothing" stuff whatever it starts bringing up as themes it usually follows through, this doesn't.
I do want to stress that I did enjoy this movie - I just feel as though the idea might not have been there to begin with and people seem to overlook the elements within the film that really aren't as strong - at least not strong enough to be considered #10 on the "Best movies of all time" list.