That's not true. The EU consumer protection laws apply to you if you bought the tickets from their EU legal entity.
If your flight is cancelled you get it refunded or monetary compensation only if you bought it from the EU website of the airline. If you bought it form another country, then the laws of that country apply. It's simple.
EU air passenger rights apply no matter the airline or where you purchased them from if your flight is from the EU or within the EU. If your flight is to the EU they only apply if it's a EU airline.
https://europa.eu/youreurope/citizens/travel/passenger-right...
If your flight is cancelled you get it refunded or monetary compensation only if you bought it from the EU website of the airline. If you bought it form another country, then the laws of that country apply. It's simple.