I consider saving in a bank with Bitcoin to be the most prominent, because Bitcoin is resistant to inflation and its value will continue to increase and if you only rely on savings, the value of your money will be eroded or even continue to decrease and will not be resistant to inflation.
Saving your money in the form of Bitcoin is a good choice and also very profitable compared to saving money in a bank that will never change or increase, unless you put a large amount of money with the deposit method and even then it will not produce good profits.
And you are right, if you really need money, you can use it or cash it out quickly. It doesn't mean that you invest in Bitcoin, you can't use it if you need it and having Bitcoin makes everything easier than money because having Bitcoin is completely in our own control and we are the bank.
You are getting it all wrong. Investment, savings, business, emergency funds and to mention a few others. All are essential in our life. We cannot do some and leave the others. All are important because they takes care of certain responsibilities when you need. The essence of investing is to be wealthy and that is why it is a long term plan. Savings is done when you want to start up a business or your planning for ceremonial event (marriage or any) in the future which you dont expect to touch your investment. Your emergency funds is for unexpected life events that comes at any time. It could be health, or utility bills.
So you see, all of them have a part to play in our lives. While we skip one or more we tend to find ourselves in a difficult situation where we can be pushed to make wrong decisions that can affect us.