Before adjusting your font settings on the Android, check the specific program you are using for font-editing options. For example, if you want bold letters in an email message through Gmail, that ...

You can't change the actual font on your iPhone, but you can change the font size in a couple of different ways, especially if you have iOS 15. ... you can also make all the text bold.

Now your default writing style for new notes will be the standard font size, no bold text. On Notes for Mac, you can find the same option by opening Notes and selecting ‘Notes’ -> ‘Settings ...