Wax sits on top of your paint like a sticker, and it's gone in a couple of months. Ceramic is different — the SiO₂ polymer flows into the microscopic texture of your clear coat and bonds to it chemically.
Once it cures, you've got a semi-permanent layer that's harder and far slicker than bare clear coat — a new sacrificial surface that takes the UV, the salt, and the wash marring so your actual paint doesn't.
That's the honest pitch: it's not a force field, and it won't stop gravel. What it does is lock in your paint's condition and make the car dramatically easier to keep clean.