The app's settings also has a toggle that lets you intuitively change the size of the text ... a preview on the same screen.

Learn how to adjust text size on your iPhone for better readability and accessibility. Step-by-step guide for device-wide ...

Microsoft Office, a few years back, changed the font size and style to Calibri. While it was a good decision, there are always some users who do not like the defaults and need a change.