Forgive me if this has been done to death here, I’m relatively new to this sub. I personally always felt it was more poetically beautiful for Bojack to die. The tragic (anti)hero meeting his end after a chaotic life of destruction to himself and everyone around him. I don’t hate the ending we have, but I always felt there was a certain beauty and closure that felt right
I think the point is that the writers did not want a “poetically beautiful” ending. Suicide is not supposed to be beautiful and seen as the “right” ending for anyone. A major theme of the show is how reality is messy and often does not line up with what we think “should” happen in our imagination. In the same way that there are no happy sitcom endings in real life, I think the writers wanted to drive home that there aren’t any tragic cathartic endings that we might dream up in our imagination either.