There are things called restaurants, take away delivery, deli selling ready made food..
I do just as little in a rental than in a hotel, with added bonus of separate rooms, plenty of space for the kids, and a proper kitchen with fridges etc to store snacks and drinks
Yes, so you have to go and find shops and delis. Even if you order in takeaways you still need milk and coffee and snacks and other basics. You still have to clear up afterwards, wash dishes/ load and unload dishwasher. Or go out for every meal not have room service and it cleared up for you.
For me personally, with a full time job and so much else on my plate as a lone parent and some health problems the holiday is for my children's benefit but also because I actually need total rest as well, just for two weeks per year, because the rest of the year I have to do everything and function on 2-3 hrs of sleep per day.
Obviously, people's situations are different, and what they want from a holiday is different, and hotels will cater to whatever they think will earn them the most money... hence providing cramped rooms with sub-optimal options for flexibility of sleeping arrangements in many cases. I just find it odd when hotels market themselves specifically as family hotels and then provide "family" rooms (or "suggested" rooms for 2 children and either 1 or 2 adults) that will be the less preferred option for most families with children, most of whose children would prefer two single beds to a double bed.
The additional space/ cost to change a double bed (that is being marketed as large enough for two occupants to share) to two singles that can be converted to a double so people have a choice, would not result in a significant enough saving in the price charged to make it preferable for many people, one would think. In many smaller, boutique or family-run hotels in Europe a more traditional and practical "family room" setup is still more common. Not much of a holiday if the accommodation is impractical and uncomfortable! But I think many of the large, mass-market hotels sadly just focus on price these days rather than guest comfort and try to pack in as many people as possible, as posters have said.