Cooking definitely do. My groceries bill is around 150€/month. You'd need about 750€/month to eat out twice a day. The difference is 7200€/year, a pretty hefty chunk of your post-tax income.
Yes! I did not eat in a restaurant for 15 years. It helped my family never did so I did not miss it. Perhaps a tip for people trying to future-proof their kids for economic depression.