I wouldn't label it a necessity. Since a Roku player is primarily designed for use with online sources, those sources will always be formatted correctly. Since it also has the ability to play local media, it would be a nice feature to have. You really can't compare it so computer based software, as they have two different purposes. That said, I would really like a version of VLC for the Roku, but the developers say it will never happen because the Roku software language is incompatible with what VLC is written in, and they won't spend the effort on a completely separate version. Can't say I blame them.
Dan Roku Stick (3600), Ultra (4640), Premiere (3920), Insignia 720p Roku TV, Sharp 4K Roku TV, Nvidia Shield, Windows 10 Pro x64 running Serviio and Plex on a wired Gigabit network.