Why does printing from Apple devices still use huge fonts?

Make sure when printing, that the printer setup page is not showing any Zoom setting and the correct paper size is selected.

For Outlook, there are many suggestions on the internet for the Outlook printouts being too large across all device platforms and printers. There are options in Outlook for adjusting the zoom level, independent of the font point size. As a test, save the Outlook output as a PDF to get an indication of the size of the printout determined by Outlook, without using AirPrint at all.