What are the main problems that may arise if all countries close (or almost close) their borders for 1-2 years or more?
Fortunately, it cannot be said that some kind of isolation is felt now, because we can easily call (Skype) a person who lives in another country.
But what problems can arise?
I don't think there will be any problems, as long as the products and services can cross borders. Personally I have my family spread over two continents and 4 countries, some I haven't been able to see for years for different reasons, and that doesn't make me crazy or depressed.