Closest equivalent of dstat on mac
Dstat is a versatile replacement for vmstat, iostat and ifstat. Dstat
  overcomes some of the limitations and adds some extra features.


As you said, iostat is available on macs. But, additionally you can install ifstat using homebrew by typing the following:

brew install ifstat


To install homebrew -if you haven't it yet-, just use the following command:

ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"