And let's not forget...until the day comes that an online provider can't delete your legally-purchased "digital download" from their library "because the content owner didn't renew our license to host it" -- or worse, "the content owner has decided to open their own streaming service, & don't want that content available on any other streaming/online provider until long after they can milk it for all the money they can squeeze from it", DVD purchases provides the only guarantee that you retain control of your ability to watch it.
but you don't need the portable DVD drive to watch your own rips- this entire design is aimed at folks who find digital rips to be too hard
if you just want to playback digital rips, there's always cheap android tablets/Chromebooks or atom windows boxes