I appreciate your thoughts about this matter, anodecathode. I'll explain further details about the compatibility version of QuickBooks Online (QBO).

The QuickBooks Mobile app requires iOS 16.0 or later. However, you can still access QBO via the Safari browser on iPhones running iOS 11.1 or later, provided Private Mode is turned off. To learn more about the system requirements and supported operating systems for the QBO mobile app, please visit this article: QuickBooks Online access for mobile devices.

Please don't hesitate to reach out if you have any further questions.