Florida was a tourist destination long before Disney.
https://flaglermuseum.us/history/flagler-biography
That's a big part of why Disney chose Florida.
Disney World was a game changer, but Florida was already a major vacation destination. Spring break was already a big deal by 1960.
Weeki Watchee was one of the nation's top tourist attractions as of the 1950's. Gatorland opened in 1949.
Ripley's Believe it or Not Museum opened in 1950. St Augustine was already home to the Castillo de San Marcos.
The Castillo is the oldest masonry fort in the USA, and is over 450 years old.
The Ponce de Leon Fountain of Youth Park dates to the 1860's. Silver Springs State Park also dates to the 1860's.
Indian River was also a draw: home to the top FL orange groves.
Kennedy Space Center was a significant tourist destination staring in 1964.
Florida officially adopted the name "Sunshine State" in 1970.
And of course, there's the Everglades.
Disney piggybacked off many pre-existing attractions.
Would Universal have chosen FL without Disney? That is a good question.
Sea World opened in 1973. It was predated by a long list of other animal attractions: Alligator Farm (1893), Monkey Jungle (1933), and the Serpentarium (1972).
It is entirely possible Sea World and Universal would have chosen to open parks in Florida if not for WDW.
Universal was already doing theme park entertainment before WDW opened. Universal Hollywood's backlot tours started in 1915, though the tour was discontinued for a long time, it was reborn in 1964. The first attraction was War Lord Tower in 1965. There was also a petting zoo. A 1968 Screen Actors Guild rule = the studio tour shifted significantly towards theme park experience, as they could no longer allow tours on live movie sets. Universal started adding theme park attractions in 1968, with several opening in the early 1970's.
Now of course that came after
Disneyland, but it is very likely Universal would have developed without Disney. Coasters predate Disneyland by a wide margin. Leap the Dips - not the first coaster, but now the oldest in the US- dates to 1902.