Don't assume she's down yet tbh. She survived BMs attack prior. The idea is that ancient zoans have extremely high recovery.
I have a big feeling she gets up again and that will be used to address the fact that they need to start using Kairoseki to keep them down. They are literally on the island where Kairoseki masonry is a thing
Up until now this was always Nami’s most unsatisfying fight, but the Wano isn’t close to over to i wonder what Oda is gonna have her do... maybe she’ll get another matchup or help defeat the numbers with Usopp and Chopper