I do so many things at home that are not "worth my time", but if I could trade doing them for more hours sitting at my desk would I do it? No! I spend enough time working. Some people enjoy cooking, gardening, yard work, etc. There are days that pulling weeds is a nice break from sitting at a desk. I'd never want to work every waking hour at my job so someone can cook, clean and take care of my house for me. Some things I do - are they worth the money? Not a chance. Worth my time? That all depends on how you'd rather spend your time.
2. The whole "my time is worth X at work so it is worth paying X to not spend time doing something myself" is a fallacy. That only applies if there is opportunity cost involved.
3. Unless you pay even more for delivery or the pizza place is right next door, it will take you 15+ minutes to drive there, pick up the pizza, and come back.
> Not only do a save a lot of money
So, it's not cheaper.