We do this. New stuff I buy has no sentimental value attached and if it can't be easily maintained, I have no interest in it. When in doubt (which is rare because we typically do our research before purchasing) we chuck it in the dishwasher...
Don’t put nonstick pans in the dishwasher. They will retain their nonstick far far longer if you always wash/dry them by hand.
Keeping knives sharp seems to be hard if you put them in the dishwasher. Maybe your friend just sharpens them a lot?
As long as you put them in where the blade won't hit other items, i'm not sure it'll actually do damage to the blade itself. Wooden handles could be damaged, but otherwise I think you're fine.
Electric sharpener is another nice timesaver but decent knives can still be "sharp enough" even if mistreated, for those weird people that are fine with half-dull knife