For my dad, he occasionally composes Word documents and uses other MacOS software for his business, so finding analogous iPad software and teaching him how to use that wouldn't be worth the effort.

iPad could probably work for my mom, but she just uses hand-me-down macs from my dad or me/my siblings.

Microsoft Word is available on iPad. I believe it’s a port of the real thing and thus has full file format compatibility.

The issue is old people don't like change. If an older person is used to the WIMP interface there is no point forcing them to change how they do everything.