The greeks were considered lost when the ottomans came in - no state no army no nothing. The Germans, the English and the french were the ones that “re-discovered” the Classical greeks in europe and used them as their own identity cores for what they believed their civilization is. The problem was that when some peasants from the mountains managed to liberate form the Ottomans and create Greece as a state, their whole identities now were shaken considering that there are actual greeks that are the “true” descendants of that civilization. And of course many scholars, especially Germans in the 19th century started exploring facts around how Greek are the Greeks and there is a specific German wave of scholars saying that they are not Greeks. This was actually for two centuries the case until actually they managed to do DNA tests of today’s Greeks and using some samples they had from bones in graveyards of the periods before even the classical era discovering it’s mostly the same. Regardless of the fact that we as Greeks are similar to the ones lived here like 3000 years ago this has nothing to do with the fact that this civilization survived and it doesn’t have to do at all with any genetic similarity. On the contrary, it actually has to do with stuff that has nothing to do with genetics, but with how the Greek civilization has managed to transform over the years without losing its essence and that is what makes the Hellenic civilization the greatest one. Also don’t forget that when the west had its medieval times the greek world was flourishing with the Eastern Roman Empire which was Roman only in its name so they of course envied that.