Venice is a small city compared to Jakarta, and they're moving Jakarta. However I'm not sure if they will succeed in their plans with Jakarta, sure the big companies will move, but moving a city is not a trivial thing to do.
By comparison, since 2020 the Lagos population grew by more than the entire population of Abuja.
More realistically, Northern Jakarta is sinking, but the Southern part (and the suburbs/exurbs in the surrounding area) are still going to be okay and Jabodetabek will still be home to millions.