We have a food processor. I used it only for the following:
1. To shred any large quantity of cheese. Saves your arm big-time.
2. To make pesto once or twice a year from the basil in the garden. (Just whiz it around with olive oil, garlic, put into ice cube trays and you’re set for the winter.)
3. To make a slush of tomatoes that need to be picked from the garden but don’t have any particular use when I don’t feel like canning. The tomato slush freezes very well in a ziplock bag and will later make awesome pasta sauce.
Other than that, I don’t personally have much use for a food processor because I enjoy chopping vegetables by hand if I’m making something like salsa or a stir fry. I can make dough in my Kitchen-Aid stand mixer if need be.
On the other hand, it’s hard to resist buying a brand-new, shiny, super-powerful Kitchen-Aid food processor to match the mixer. So far I’ve resisted, by remembering how short the list above is!

Ah! Thanks for the insight : ) I actually enjoy the whole by-hand chopping process too, so kind of felt the same way about their usefulness vs cost (not to mention storage).