The price of materials and overhead, and to show a bigger profit to shareholders. The profit may be the main factor. The others can be an easy excuse to raise prices. The stop start system cars take AGM batteries I understand, cost 150-200. I gave my 07 Prius to daughter with 68k on it. She loves it, but the small AGM battery is about $200 now. I managed to get one for $140 on a sale. Very small battery Optima, made by Johnson Controls.
Cars were cheaper too. A pickup truck starting at 25K before taxes and license for a basic model? Maybe it's more.