I've visited uncrowded beaches in Florida, they are there, but kids prefer the other kind.
We visited Miami Beach and it was pretty quiet when we were there. We stayed across the street from a sliver of a park and then beach.
The wife tripped on a sidewalk and burst an artery in her forehead, and also ruined her shoulder at the same time. Had an interesting ride in the ambulance, they took good care of her. She was really bleeding.
She had the shoulder done last August, the full monte, unlike mine. She said it was really bad, the recovery. rotator cuff.