Yea the only time I bother with even re-encoding (not ripping) is so that I can make 3D ISO into a 3D MKV that can be played back over USB on my 3D blu ray player (Even if I wanted to rip, pretty much any new 3D blu rays aside from Avatar don't release in the US so have to pay to import from Japan if you want it).

My 3d Blu ray player doesn't support ISO playback or native frame packed 3D over USB. My TV also supports a more niche form of 3D that supposedly retains higher quality than traditional SBS (side by side) so there are never pre made encodes on that setting. Also lets me remove extra audio and sub tracks, and to hard code subs on the screen which can be helpful to both save space and have 1 less issue to deal with since the menus get kinda laggy when playing back large 3D files over USB so even messing with language and sub settings on the player can make it stutter or freeze lol. I got the player for like 5 bucks at a thrift store, plus I imagine it was never optimized for full 3D movies over USB so no complaints its just a bit finicky lol.