Most applications clog up the cache space on your device’s memory. You have to delete the cache manually which is not convenient. Fedilab is one of the few applications that has a self-cleaning cache function when exiting the application. Why don’t many other apps have a feature to disable caching or self-clear the cache?
A lot of caching mechanisms are not based on time but size. In other words, they have some set limit of space they can take up on your device. Once that limit is hit, they start evicting older cached data. This means the cache will never be cleared but it also means it shouldn’t grow unbounded.
If an app you’ve installed is “caching” and it has no eviction policy and can grow unbounded then that is a pretty big bug.