The primary purpose of a book like this seems to be so that the author can go on a tour around the world and write the costs off as a business expense. If the book sells well, that’s just gravy (pun intended).
Other than that, National Dish is as much a thing as National Language. Take Latin / Romance languages for instance. It's something of a trope that in the old days (before modern communication and standardization of "national language" with one dialect proclaimed "the reference" and evangelized through media), going from Rome to Paris to Madrid meant every two adjacent villages would understand each other but 100 villages away this would cease to be true. Language changed so it makes just as much sense that food recipes changed.
This is brilliantly illustrated for the Balkans region by Key & Peele's sketch "Macedonian Café": https://www.youtube.com/watch?v=g1KiFON-GWg
There's "Ćevapi" as "national dish" of Bosnia, a country the size of a pea grain so sure, THEY invented it. In fact it's the exact same situation for Latin dialects. Go from Bosnia to Serbia to Romania and every two villages will make a ćevapi that's similar enough but 100 villages away the flavor and recipe would have changed enough to create the "Macedonian Café" situation :)
That being said, it is a comedy sketch, so ultimately it’s up to interpretation.
The recipes appear the same but there's subtle differences. Exactly the situation in real life and they chose, probably knowingly, the one food that's very controversial and every nation around claims their recipe is the best.
Ćevapi -> ćevapčići -> mici (Romanian). I can understand Kay and Peele's sketch because I feel exactly the same looking over the Bosnian / Serbian recipe and it's nothing nationalistic here. Only a lot of "chef" pride: we got the best recipe in town, everyone else is subpar. Like what do they think, eat it with onion and cream? Disgusting! Proper way to eat mici in order to savor their flavor is with just a little bread and mustard: https://i0.wp.com/sunt-sanatos.ro/wp-content/uploads/2020/05...
You can eat them with fries, salad or what else but you're effectively trashing the effort of the cook. Like ordering an expensive and rare Kopi Luwak coffee and drowning it with sugar and milk and ordering a cola on the side to add insult to injury, I guarantee that the barista will smack you in the head if you do that.
Brilliant, really.