Yeah, I see that it is difficult to actually convince you that your smartphone is pretty unsecure. Its not like almost every app can access your filesystem and steal your wallet right?
That's not a real problem.
Of course your wallet app is "absolutely" insecure, which I already mentioned.
The point is, security always is relative. There is no such thing as an absolutely secure system.
For smaller amounts of money, the sums you would carry along in your day-to-day wallet app, it simply doesn't matter. There's no need for your wallet app to be more secure than your cash wallet.
Again, your card definitely is less secure than your mobile phone, simply because you have to give up physical possession of it for payments, if only for a brief period of time when the card is inside some POS-terminal. Your smartphone can stay in your own hand all the time. No need for anything but an air-gapped scanning of QR-codes required. That's pretty secure.
If you think about viruses, trojans, whatever for mobile phones, you're right, though. Wallet apps could become a lucrative target for those. But that's actually a trade-off between security and comfort, which is a problem without a solution so far, no matter what technology is used.