system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do computers inevitably become slow and glitchy overtime?
gpt
The slowness is less about the computer itself and more about the software... mostly. Unless you let your computer get jammed up with dust or the fan is damaged, computers don't really get "slower". For example, well maintained gaming consoles (which are computers that just are specialized for video games), from the Gamecube to the Atari 2600, will play their original games as today as well as they did the first day they came out of the factory.

If you don't properly maintain your computer, things can get damaged, either limiting performance as the computer automatically uses less power to keep itself cool, or problems with parts of the hardware can cause all kinds of weird glitches.

However, the reason most computers start to feel slow is because of the *software*. When Microsoft updates word, when Youtube adds features, when entirely new software hits the market, they are expecting their average user to have more and more powerful machines. They stop optimizing performance for older CPU's/GPU's, start expecting their customers to have greater and greater amount of RAM and faster Harddrives. 

Your computer isn't running slower, it's just being asked to run more and more calculations than it used to.