system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 Why are we not supposed to use phone cleaning apps?
gpt
For one, Android uses an SD card for file storage rather than a traditional hard drive. SD cards are a type of flash memory — similar to solid state drives — and don’t need to be defragmented. In fact, one of the downsides to flash memory is a limited number of times that data can be written to the card before it expires. By defragmenting an SD card, you can decrease its lifespan.

When you clear apps from RAM, Android is just going to load them into RAM again the next time it needs to access those apps (for notifications, updates, and other background details). This is actually slower for you since SD cards are slower than RAM.

And in the case of automatic task killers, you end up having to sacrifice some of your RAM and CPU to the task killer app itself, which is always running and monitoring for opportunities when tasks should be killed. This can be a big drain on battery life — and you aren’t getting anything useful in return!