I think Android dev is unnecessarily designed in a way that makes saving data require a lot of code. If you know what you're doing, you can mmap a file, put all your working memory in there, and let the OS save it for you. No serialization or parsing necessary and memory access is exactly the same as usual with no overhead. You'd think that using a managed language would make it easier to abstract and support this kind of thing but seems they'd rather require all app devs do manual saving and reloading of their app data.
How to kill solid storage with one easy trick!
Please don't do this.
They might also be lacking competence. My local bus authority’s application is barely able to keep track of its state while it’s running.
An other common situation is an applications getting in an irrecoverably broken running state. If the application preserves state on shutdown you might not be able to get it out of the broken state.