No you're not missing anything as far as I can .
Unless you're into home movies or are ripping old VCR or Laserdisc material and want to minimise the size of files you create then DivX and its' ilk such as Xvid and others really aren't a lot of use any more IMHO.
In the days before DVD burners then the idea of compressing a DVD down to the size of a CD or two while retaining reasonable quality had attractions .. if you were inclined to copy DVDs

. Nowadays with DVD burners selling for £30 then I see no point whatsoever in continuing to use DivX for that purpose.
Maybe I too am missing something, but I don't think so.