In an ideal world, we would be able to get our fruit only from outlets who present it in cardboard containers, or be able to take our own.
If only life were like that!
I reuse many of mine, but by the time I've reused them they're rubbish, not recycling - so I'm not sure it's better.
As to what I use them for, any time I need to carry several small things about; the large one without holes act as temporary waste and compost containers in the kitchen (saves me a lot of walking!), that sort of thing. Usually unusable and unrecyclable afterwards, though.