It's an interesting point you make about the effort involved in making a dish. I'm on a mission to eat, and mostly home cook, food from as many countries as possible. I'm at about 25% of the world's countries now after several years of gradual chipping away.
From that experience I feel that there are some food traditions which will be more durable than others and, as you suggest, this is not just a matter of tourist influence but I think capitalism/market forces are behind most of it.
Factors which I think will work against long term survival include:
-high effort: more families where both parents work for money and where the family unit is very small mean fewer opportunities for elaborate preparation. In my family we think of that type of cooking as a luxury afforded to us because we are wealthy enough to have enough free time from work to do it once in a while, but in the cultures where the food originated it was built into the schedule.
-scarce ingredients: 25% is a lot of the world's countries but I know I will never reach 100%, even if I live to 110 years old. Some countries, especially island nations, have specific local herbs and vegetables that aren't available elsewhere. Over time, the market for cultivating these will decline as it is squeezed out by cash crops for export or non-indiginous crops that grow more reliably or productively. This has happened to some regional foods in my (western) home country and while they are still available, they at risk of disappearing. Another reason for scarcity is overuse e.g. with herring overfishing and surströmming scarcity.
-banned ingredients: as food standards regulations around the world gradually harmonise to allow free trade, some ingredients will be banned. This is an ongoing global war which will carry on for decades, but it already means that some cuisines aren't available in other territories. In the longer term they could be lost from their home countries (bush meat etc.). Again surströmming features in this category and only has a temporary reprieve from the EU.
-unavailable methods: in some cases it's already a stretch to say that I'm cooking the food of a country when I'm improvising with the methods and materials. I don't have a tandoor in my back yard or a wood-fired oven for baking shakh plov; I've not really got the option of digging a hole to ferment some hákarl either. With increasingly urban populations globally, many traditional cooking methods will be unfeasible for most people.
While there are good reasons for some of these influencing factors, like food safety, others are clearly unintended side-effects. There is a strong (non-economic) case for national governments dedicating resources to conserve their cultural heritage by giving their local cuisine some protection from external pressures.