The costs of some things have indeed plummeted. It still costs a lot of money to eg. close off city streets, hire cranes, ensure 200 cast and crew are in the ri

The costs of some things have indeed plummeted. It still costs a lot of money to eg. close off city streets, hire cranes, ensure 200 cast and crew are in the right places at the right times with the right skills and equipment. Also marketing is typically a huge chunk of the cost involved. Btw lots of frame-by-frame retouching happens on modern movies. Doing decent VFX is extremely laborious.