I've taken to using baking paper with most oven cooking, it works pretty much as well as foil and is cheaper. I rather like soggy microwaved potatoes and sweet potatoes - topped with whatever is around. Maybe the variety makes a difference?Can bake/roast some whole veggies like potato/sweet potato/pumpkin/ etc in a convection oven. Just put them on a baking tray, maybe with a light drizzle of oil and some salt and favourite herbs/spices. Also can wrap them in foil, which reduces tray and oven cleaning.
I agree food processors are mostly too much effort. And I agree with Jonathan that a small thin bladed knife can do most cutting jobs. And a suck-on knife sharpener is great.I've tried various gadgets but found getting them out of the cupboard (don't have enough bench space to leave them out), scraping the food out then cleaning and putting everything away again was just as much effort as prepping by hand.

The one chopping gadget I can be bothered getting out sometimes is a stick blender. I have a Kenwood. It has a detachable metal stem and cutting head that is easily rinsed under the tap at the end of the job. It's good for pureeing a pot full of veggies into a smooth soup. There's no extra container to wash, as the blender goes to the pot. (Though, most stick blenders come with various other cutting and whisking heads, including some containers for grinding nuts and the like, so, if you really do want to wash a container, you still can.)