I think the safest option compared to trading and all that is the fact that as long as there is no hacking involved you are bound to make money. If you are considering bitcoin as a whole for investment and decide not to invest into bitcoin then yeah you can invest into something "safer" yourself.

So, the "safe" here is not for the people who are holding fiat and considering what to invest into, the "safe" here is the people who have bitcoin and don't know what to do. If you have bitcoin at your hand and you are going to invest into something eventually its safer than trading because in trading you may lose money if you buy high and sell low but in casinos you invest and you keep making profits after profits which increases your bitcoin holding in the long run.