Paris is actually pretty small by area, especially compared to the other cities you listed. Paris is ~100 km² while Mumbai is ~600 km². Paris has a population ~2 mil and Mumbai has a population of about 12 mil so they're very close.

This chart is just weird because it doesn't define "city" and OP just ripped their data straight from the Wikipedia page "List of cities proper by population density" without any real thought or research about the topic. It does feel like a karma grab. But you also shouldn't say it's wrong just because other cities feel like they should be denser.