When you have no cash (or some other asset as liquid as cash-might be gold or bitcoin), you will stay vulnerable to a financial crisis. They don't want you to stay liquid. They want to bury you down with Real Estate investments, Iphones, Car loans... When the shit hits the fan, you won't be able to lift a finger and banks will you rip you off one more time
As to me, that's mostly bullshit
If they actually wanted to rip you off, they could do that with cash as easily as with any other money (digital or otherwise). You seem to have never heard of confiscatory monetary reforms when all cash is announced null and void overnight (yes, exactly that happened in the past with some currencies). In this manner, cash is no salvation either (let alone a safe haven). Bitcoin in this aspect looks more promising overall, but you should still never forget that money is not wealth itself