I've never known a dishwasher that doesn't :
a) require you to rinse the plates/whatever first or
b) end up with a dish (or three) that still has scraps of food attached.
Ours is currently disconnected, and I'm happy to wash by hand.
Having recently bought a new, high end Cove dishwasher, I was given a lesson on this. With older and/or cheaper dishwashers, it's better to pre-rinse because they simply don't do that great of a job. But, with the newer, higher quality dishwashers, you don't have to pre-rinse, except for soaking/scrubbing off an really caked-on, dried food residue. In fact, the dishwasher will clean your dishes
better if you don't. The newer ones have turbidity sensors and filtration systems that adjust the wash cycles based on what they detect. So if your plates are already rinsed, the wash cycle with end sooner before getting your dishes fully clean. Also, detergents apparently work best when they can react with food enzymes to really get the full benefit of their cleaning power. I was dismissive of that at first, because it's so counter-intuitive and "rinsing your plate" was what everyone did before placing them in a dishwasher. So, the first thing I did with the new Cove was to load it up with really dirty, unrinsed dishes to see for myself, and son of gun, I've never had cleaner dishes! (I won't lie, though, it's a hard habit to break!)
The only thing I don't put in the dishwasher are my good knives, wooden spoons/spatulas, bare cast iron, a nicer flatware set that has stag handles, and for some reason, my All Clad stainless pots and pans. I don't know why I don't put the latter in there. If they're made to be placed on an open gas flame, it's not like hot water is going to hurt them. Still, I just can't bring myself to toss them in there.