iOS is a little more strict about how applications use memory. Apps need to expect to be terminated at any time and be able to suspend their state with a few seconds' notice.
The reason is to give you better battery life and fewer issues caused by limited available memory.
That's not a reason, that's an excuse. The solution is that Apple implements a reliable pause and resume system so that its multitasking experience isn't inferior.
The reason is to give you better battery life and fewer issues caused by limited available memory.