Corfu is worth visiting, and more seriously than most people treat it. It has been a destination since antiquity and the depth shows. The Venetian Old Town is a UNESCO site with a coherent urban fabric that most Ionian island tourists fly over without stopping. A day in Corfu Town done properly, on foot, without rushing, is one of the better days available in the Greek islands.
The beaches require some navigation. The best sandy beaches are on the west coast and the northwest, not the areas closest to the airport. The east coast near Corfu Town moves fast in July. Paleokastritsa is dramatic and justifies the visit; go early in the morning.
The cruise ship question is real. The impact on the island is documented and not trivial. If you arrive on a ship you are contributing to a system that the island itself is trying to manage. If you stay, you are part of the economy that funds the place. The distinction matters.
Easter in Corfu is unlike anything else in Greece: a public, spectacular, liturgical event that happens in the streets and is worth organising a trip around if the dates align. This is not a recommendation aimed at religious tourists. It is a recommendation aimed at anyone who wants to see a community in full expression of its own culture.
May and June are the right months. The island is functional, the prices are rational, and Old Perithia in the north, an abandoned Byzantine mountain village, is accessible without a queue.