Florida was a vacation spot before WDW. Winter Park, Ocala, Cypress Gardens, and both coasts had vacationers. Riverboats traveled the St John's River in the 19th century, and Flagler built a railroad so people could get to St Augustine, The Breakers in Palm Beach, and resorts in Miami. The same with resorts in Sarasota, etc.
The wealthy would winter in Florida, and in the 1950s, with better roads, the middle class began vacationing and traveling the state to visit places like Silver Springs, Weekie Watchie Springs, Marineland, etc.
Florida tourism didn't begin in 1971, but the addition of WDW, along with affordable flights, A/C etc certainly made it boom in Orlando, while the attractions elsewhere faded, if not outright disappeared.