Why are most circular pizza peels designed with holes in metal
The Chef Pomodoro round peel you picture is described by the manufacturer as a ‘turning peel’.

A turning peel is a must-have to easily rotate the pizza multiple times with precision.

Taking that cue I checked a few more on Amazon and they were mostly described that way.
A Turning Peel is specifically for rotating the pizza while it is cooking. I imagine that the radial slots allow increased friction making it easier to turn the pizza. I don’t think you could use it to put a thin, fresh, homemade pizza into an oven.
One reviewer of the Chef Pomodoro peel says:

The turning peel worked great and freed up my regular peel so we could keep making pizzas inside while I was cooking them outside.

which indicates a separate function from a peel you would build a pizza on.