A good wax is is good enough protection for normal dirt, dust, bird poop, and other non-abrasive substance.
Film protection protects all those plus the impact of small stones and rocks that gets thrown around, i.e. paint chipping. Not 100% protection but good enough for 99.9% of the stuff.
Some people are religious about filming their paint, some are not, it's a mostly personal choice. I didn't film most of the painted surface of my 918, only the exposed carbon bits, I believe the basic basalt black is simple enough for any bodyshop to respray. I was planning to film the RS because of the Lava Orange, but after a rock chip on the hood, I had decided to just skip filming the car and re spray when the time comes.
--