That's code for 'cheaper'. Banks in the Netherlands are constantly trying to push all their customers to their apps, some (like ING) are actively trying to get rid of their alternative (but keep getting somewhat forced to offer it), and some (like BUNQ and KNAB) are 'smartphone only' from the start.
Cryptographically, the idea of a discrete piece of hardware that uses the chip in your debit card to generate secure responses is fairly sound. And if smartphones didn't exist, it would be an unquestioned piece of technology that might even be commodified to the point that any such device could be used by all banks in the country. But smartphones exist, and having the customer loan the banks their hardware (which is often replaced within five years, so free updates too!) is quite attractive. No more hardware to support!
Cryptographically, the idea of a discrete piece of hardware that uses the chip in your debit card to generate secure responses is fairly sound. And if smartphones didn't exist, it would be an unquestioned piece of technology that might even be commodified to the point that any such device could be used by all banks in the country. But smartphones exist, and having the customer loan the banks their hardware (which is often replaced within five years, so free updates too!) is quite attractive. No more hardware to support!