I just returned from a 10 day trip. Agree entirely w/ the OP and a couple points of interest to add
On Sanibel, eat at the Island Cow, the patio has iguanas and games, and the largest menu I can recall.
On Captiva, eat at the Mucky Duck, it’s right on the beach, has a great pub-style menu, and the beach chair bar at Sunset is an experience to be had.
Also, Orlando (and the theme parks), Cape Canaveral (Kennedy Space Center) and St Augustine (48 states’ oldest city and pirate fort/museum) are drivable and quite fun!