Bank interest is not worth it for investment purposes, they'll give you 1% while inflation can be from 2-4% every year.
Right now this is true because of all of the reserve banks trying to keep interest rates low. But this has not always been the case. Back in 2006/2007, for example, US inflation was around 3% while you could get around 5% in an online savings account. You probably could have done even better than that with CDs.
Bitcoin is indeed a safer investment strategy than many other options out there. It will always be worth something and the price won't crash down on a large scale instantly, during one hour. That means, that even if the price starts declining, you have your chances to panic sell, if you are afraid of losing your investment.
I'm going to have to disagree about bitcoin being a safer investment strategy. It has certainly been one of the most profitable if you've been willing to hang on to it through the spikes and crashes. But it is definitely not safer, which is shown by its ridiculous volatility. If it were really a safe investment, the price would be stable. The problem is that no one has any idea how much a bitcoin really is or should be worth.