[kdmtctl]

A little bit late to the party, but keep in mind that interest is a risk bound product, but fees are not. Fees are not pushing the capital requirements and generally better in terms of ROE. This is the main reason, I think.

Also, traditionally it was technically expensive to calculate a bunch of fees for every transaction and core banking systems have had quite complicated rules processing engines which were damn slow. Sometimes it was more feasible to skip a fee than take the burden. I'm not in the industry anymore but I suppose this has been changed and fees becoming the new driver.

Basically most of the Fintech was born on bank's inability to perform a lot of simple calculations and react to the market fast. The gap could be closing.