system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why doesn't youtube let you buffer through an entire video?
gpt
Because downloading videos uses a lot of bandwidth and youtube would rather you didn't download an entire video that you're not actually going to watch so they only buffer a certain amount at a time and stream the download as you're playing the video.

There are steps you can take to disable this but its not a simple setting to change.