Tbh we wash them and use them for really dirty stuff. Like when you need to remove mold with a chlorine spray or poop from your shoes. Then they get tossed because there's no way I am washing that again.
We're phasing out single use sponges though, but now I don't know what to use for the really dirty stuff.
We use a combination of brushes with wooden heads (I don't like stuff with handles though), structured cotton towels from the drug store, and sponges from Ikea called "Pepprig" which I think work best for most things. They are also plastic but you can wash them easily.