Safety and liquidity. Liquidity means the ability to use it at a moments notice and if saved that is possible whereas if invested that may not always be the case. If invested you won’t be able to use the funds immediately or at least you aren’t guaranteed that you can without a delay. The other imp reason is safety. If you save your money it is safe and retains its value but if invested it’s value can fluctuate which you tolerate and expect in the hopes that over time it will earn you more money.
