Not to discredit Yatzhee's opinion, but his views seems to be limited to the medium. In truth, every medium has problems with excesses, it is just that most of them don't have technological jumps that can be count every few years. We should all remember how a lot of "in your face" scenes started to popup at the same time IMAX and 3D became more prominent, or how The Wizard of Oz uses colors to certain extremes, because technicolor became a more standard technology. When movies started having speech tracks, the more prominent genre were musicals, so that dozens of people could be heard at once.
At the same time, its not limited to technological jumps, but sequels has that problem too: Hangover has a baby, so Hangover 2 has a monkey (and Hangover 3 might have two baby monkeys); by the end of fellowship, our heroes battled hundreds of orcs, so by the second movie, the number was upped to tens of thousands, and the third could be counted on the millions; Goku fought robots, then demons, then aliens, then alien demons, then future robots, then future aliens, then alien demons, then alien robots, etc...