Besides well publicized materials and labor shortages in new construction, the biggest reason you can't find a new construction home is demand.
Specifically, New Yorkers and Californians (any surprise here?) are streaming (literally), to Florida. In 2021, for every 210 people who moved here, 100 people moved out of the state. In Sarasota, this ratio is 311 in/100 out and in Tampa, 242 in/100 out.
Florida has always had the advantage of lifestyle and climate among retirees. The work from home trend is projected to continue, which makes a Florida lifestyle attractive to a larger home buyer group. Add to this an estimated existing national housing shortage of 6 million units, which will support continued high demand.
From my day to day business experience, I am seeing the pace of sales slowing down very slightly. More homes are now available 3 to 5 days after going on the market. Sales of homes needing any kind of work (paint, carpets, grout cleaning, etc) are also slowing down. I showed 4 homes like this to a buyer over the weekend, and all 4 are still available.
Source: Highlands News-Sun 2022, Florida Realtors