This musical has more in common with the musicals of the 60s like Camelot, Funny Girl and Fiddler on the Roof, which all begin with joy and new experiences, and descend into sorrow. But I'd say that A Star is Born is more emotionally complex and wise than any of them.
The film is certainly all about Judy Garland. I even wonder if they drew some from Judy's background for Esther's background, because they are so similar. Every musical sequence stars Garland's powerful, rich voice, and I have no complaints about that. There's not a lot of dancing, or a lot of scenes from the alternative "musical world", but some amazing music. My favorite is The Man That Got Away with a jazz combo, but Garland's performance in Someone At Last was a wonder to behold.
The version I saw was a "restored" version which had audio sections of the film restored with stills from the scenes. Although I'm happy to have the cut scenes because it made the story richer, but having long sections of stills instead of video was distracting. I wonder if I would have been better off without those scenes in overall enjoyment of the film.
Just having the dual story of rising star and falling star but married is a powerful story. Because one's gain can be the other's loss, adding up to a losing proposition. Yet, as we see in the number "Lose That Long Face" the rising star still has to act happy performing when she is torn apart. The final scenes of the film clearly communicate Esther's emotional state and give every opportunity to be empathetic without manipulation. If the end of the film leaves our eye dry, then there is something deeply wrong with us.