Cash has the same problem, which is why banks and credit cards exist. There's no reason your bank account and your VISA card couldn't be denominated in Bitcoins, affording you exactly the same protections you have now.
You might lose $100 out of your smartphone wallet every now and then. But that will hopefully be rare.
No, cash does not. There is no equivalent to issuing one command to a botnet and collecting a hundred thousand people's wallets. Cash has other problems, which is why bank and Visa exist, but there's no zero-day exploit equivalent.
It's one of the reasons computer security is so hard. What in the real world would be a minor weakness that really is unlikely to ever be exploited is in the computer world an invitation for a bad actor to "SELECT * FROM private_customer_data" and be walking away with everything you own before the alerting system you probably don't have and probably aren't paying attention to can even go off.
You might lose $100 out of your smartphone wallet every now and then. But that will hopefully be rare.