Most people on here have their own home and pay the bills needed to maintain it, rates, energy, insurance maintenance. If you do any cooking it will be in a kitchen where at sometime upi haave probably bought the cooker, fridge, air fryer, utensils etc etc. But when you prepare a meal you think only of what you spent on the food and your time.
A restaurant is no different from a home, there are premises to pay for rates, energy inssurance, standards of hygiene ets to meet, staff to employ furnishings and cleaning, kitchen equipment and every thing else, plus, of course, the cooking ingredients, which in a good restaurant will be of the highest quality
It is not surprising that quite simple dishes, when served in a top restaurant in an area where rents etc are high will be expensive. They will have more staff, higher maintenance costs, better trained staff and more expensive fittings.
Surely the highesst judgement of a chef is that he can take any ingredient, including, one, that in the past as been on a poor man's plate and make it something sublime.
Our local top of the range restaurant in France has served, in his case, beef cheek, and it is out of this world delicious, the way he cooks it, the herbs and extra he adds. I have tried to do it at home and it was nice enough, but I cannot match the flavour and tenderness it has when cooked by a top chef.
I will willingly pay the prices on his menu because he serves food that no one but a very skilled and inspired chef can provide, day after day, year after year.