system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 Why megapixels is not a good measurement of quality of photos a camera can take?
gpt
Light goes into your lens and onto a sensor, which is more or less a grid of "buckets" that catch light. A megapixel means you have a million buckets.

The more megapixels, the more buckets are crammed into the available space. This means the amount of light going into each bucket is less consistent, and more light hits the edge of the buckets instead of going in, among other things. These things lower image quality.