I have seen Joker yesterday at Venice an early ill-fated screening. We had some trouble with audio that lead to a near-hour delay, but it definitely was worth it.
Joker deserved to be presented at Venice Film Festival, an event that regards cinema as a form of art, because this film is far from a blockbuster or a mere entertainer movie, as most films in the genre are.
It focuses on the psyche of the main character, as it slowly crumbles under the pressure of society. And thus, Joaquin Phoenix does a wonderful performance, earning almost surely a nomination at the oscars at least.
It's a take on the Joker that differs from Ledger's, but I'd say that both are equally as good. The main difference might be that Ledger's joker is a rational that acts insane, while Phoenix's is insane to the root.
Despite being a movie about a superhero villain, Joker is much superior to most of the movies of the genre (I'd exclude the Dark Knight Trilogy only, but Joker is easily as good as Nolan's movies, or at least very close). It is a small-scaled film, with a distinct style and cinematography (that cannot but be appreciated) and a set of very cinephile references that however do not feel too forced or overly opressive. (most notable are the similarities to Scorsese's 'Taxi Driver' and his 'The King of Comedy', but also Chaplin's 'Modern Times' is somewhat referenced).
I am eager to see more non-comedic efforts by Todd Phillips. This movie was so far probably the best of 2019 (at worst contested so far only by Dolor Y Gloria or Once Upon a Time in Hollywood), and that should be very convincing.