Yeah I mean....of course. My sister got a cheap dishwasher couple years ago and it never broke, it just never cleaned properly, we cleaned the filters, all tubing, all the arms, used the dishwasher cleaner several times.....nope, would still leave residue and bits of food on plates, literally regardless of mode. It was basically useless for its main function. It was under warranty but the engineer came out and said yeah, there's nothing wrong with it, it's just not very good. We ended up recycling it and buying the cheapest Bosch Series 2, it's not fancy but at least it works as a dishwasher.
I have friends with cheaper dishwashers and they do not clean well at all on eco modes.
Everything's relative.