To begin it is important to explain that the over-crowding is more than because seasonal resident return. Added to seasonal residents, are their families/friends who visit + renters and their family/friends who double /triple up with them + locals and their family and friends that come to visit.
Economically its an economical boon to the area
Psychologically it is a downer for everyone where it seems to be elbow to elbow people everywhere one travels.
Realistically its Florida and places like Florida get crowded all for the same reason. Its why rich people find secluded hide-a -ways.
for the rest of us we have to grin and bear it and be polite because it isn't anyone's fault and everyone has a right to be here.