system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do VHS tapes degrade the more you play them?
gpt
In two ways.

First, VHS tapes are printed on a thin and very flexible plastic film. As you play them, that film is wound through and around a number of handling wheels and trolleys. This places stress on the plastic, stretching it over time, and any dirt or grit in your machine amplifies these little stresses. Eventually the film is pulled so much that the magnetically encoded information on it no longer reads as well.

Second, the magnetic coating itself degrades over time. Your television and VHS machine both have electrical fields that can influence magnetic writing if things get too close to them. And simple aging of the tape will help this along.

The same thing happens to cassette recordings of music in the old cassette players, particularly in cars where there's a huge engine just in front of the player and a lot more grit depending on where you live.