I visited the dog beach on a Saturday in mid-July and right now, as I'm writing this, the beach is almost empty, while this morning there were around twenty swimmers there.
There are patches of posidonia, which indicate a clean sea that should not be removed for the enjoyment of swimmers: the sea will naturally take it back.
The beach and the pebble coves hidden among the rocks are perfect for those seeking peace and quiet, even if you don't have a dog.
The lack of basic amenities like trash bins or water fountains for both two-legged and four-legged visitors is noticeable, but that doesn't excuse leaving dog waste or cigarette butts scattered around (not cool, as always).
Simply bring a garbage bag and dispose of everything properly and legally.
There is also a convenient free dirt parking lot just a few meters from the beach.
In short, if you're looking for DJ sets, entertainment, cocktails, trendy people, etc., then you should look elsewhere.