Etios top trim sold with navigation, DVD, digital TV, Bluetooth, and no rear speakers.
The system does support rear speakers and the car is ready for them to be installed, but Toyota doesn't.
It might depend on the market and I think there's a limited edition with everything in India (but likely without digital TV because the country uses DVB-T).
I’m going to guess that headunit is from other older Toyota models. At this point I think the only reason the main reason they DVD players is because there’s probably a negligible cost difference with CD players. It’s probably cheaper to use older headunits than develop new ones.
I’d say an Toyota Etios is a bit of an obscure example as it’s pretty much sold in less developed countries with very high car taxes, where cutting costs is especially important.