Technology should do at least one of the following:
1) Enable us to do something quicker (where it is significantly better to do it quicker)
2) Enable us to do something we couldn’t do without it (where being able to do those things is significantly useful)
3) Enable us to do something better (where the increase in quality is significant and useful)
4) Produce other unique effects (that can’t be achieved (better) via other ways)
Before applying this to dishwashers, we need to eliminate confounding variables.
We almost certainly:
1) Use excessive plates, cutlery, cups. Whether we could simply use our hands, or don’t reuse perfectly good plates/cutlery/cups.
2) Let food harden on plates, don’t finish our food, leave plates messy, etc.
3) Own and use regularly way too many plates, cups, knives, etc. It is much more efficient to own less and use less. And reuse more.
Now, after eliminating these confounding variables and bad habits, how useful are dishwashers REALLY?
1) Do they enable us to clean cutlery/plates/cups quicker? Not really. If you wash something straight after using it, and only use it when you need to, and maybe reuse it once or twice, keeping everything clean is quick and continuous. There would literally NEVER be any dirty dishes anywhere. And it would very likely take the same amount or less time than using a dishwasher.
2) Do they enable us to do things that we can’t do without them? Nope.
3) Do they clean plates/cups/etc better than hand-washing? Only if you let food harden and don’t clean the plates well.
4) Do they do other various things that we can’t get without them, or is harder to get without them. Nope.
These categories may not be exhaustive, but you see how it goes.
Oh, and not using a dishwasher probably saves water and electricity, and money. And space. And your house looks nicer without the chance of dirty dishes being anywhere. And its a good habit to clean things after you use them (see further reading).
So, sell your dishwasher and 90% of your cups and plates and cutlery (maybe keep a few extras for guests, but know that what you THINK is a good minimum is probably a little to high. Maybe a lot too high). Then, start applying this process to all other technology you use. Have fun 🙂