Have full PPF on the front, ceramic on all the rest of the vehicle, as I do with most of my vehicles. Almost ran PPF down the sides as well to provide additional protection from pin striping, but ultimately decided not to for no real reason one way or another.
Anyone who tells you that ceramic provides anywhere near the same level of protection as PPF is lying to you.
Consider ceramic a significantly better wax. In the end, that’s what it gives you. Shine, “slickness”, etc. PPF is a physical barrier outside of your paint that can provide additional protection against abrasions, etc.
Have seen a vehicle with full PPF have the rear quarter and bumper swiped by another vehicle, transferred paint. The metal and plastic did not get dented thankfully, and the PPF took the full brunt of the hit. Peeled and replaced, this would have been a respray of the bumper and the quarter if no PPF.