They need not be mutually exclusive. Yes, requiring that all apps go through the App Store means Apple is able to efficiently get a cut out of every transaction, and it can also mean better security for its users (in the very least, I have not received any reports of this particular scam impacting iPhone users). The issue I cited has garnered so much attention in my country that some of the banks have taken to updating their apps such that they no longer work on android phones if the presence of side-loaded apps are detected.
Additionally, if users want to extol the benefits of sideloading, then I wish they would at least also preface their statements by also acknowledging the risks and pitfalls, rather than sweeping said issue under the carpet and pretending that everything is rosy and there is only pure upside with zero drawbacks.