Regarding travelling to Corfu, the airlines flying from Athens to Corfu are Olympic Air https://www.olympicair.com/en & Sky Express https://www.skyexpress.gr/en/.
Sky Express & Ellinair https://en.ellinair.com/ also fly from Thessaloniki to Corfu, but not daily.
Furthermore, there are several charter flights landing to Corfu from all over Europe. If there is a direct flight depends from where anyone is coming from, otherwise the only way is flying through Athens.
