The ending is a bit overblown but all in all I thought Babylon was great, though I fully understand why it hasn't done well commercially - an old fella in my screening walked out in the first five minutes when he saw the golden shower scene.
It's an interesting counterpoint to Once Upon a Time in Hollywood, partly because Pitt and Robbie are in both but mostly in that they're fairytales about Hollywood history, but this one had far more life and humanity in it. Interesting that Tarantino obviously sees the Manson Murders as the point when Hollywood lost its innocence while for Chezelle, the advent of sound is when it gained a false and hypocritical air it packaged as innocence.
I've seen people describe Babylon as a depiction of how assimilation represents choosing to kill a part of yourself to chase a dream, and there is an element of that. But it seemed to me more a love letter to the people who made up the silent movie era, behind the camera and in front - the people who never really got to speak, not least because they didn't fit into the newer Hollywood's idea of itself. Chezelle's love for jazz also shines through. The score is superb and there are plenty of scattered silences which are well placed to heighten the drama, the idea that the music stops briefly and will one day stop for us all. It was a very enjoyable evening out.