Earlier quoted context omitted.
But who uses RTF? I can't recall ever receiving an RTF file. Scanning my drives, I've only found a single Readme RTF file in some old Windows utilities.
I haven't created an installer for a Windows desktop app in over 5 years, but it was a common format for the embedded EULA. It's not as important these days, but there was a huge file size difference between an RTF created in Wordpad vs Word.
In fact rtf usage is all over the place on Apple platforms. Cocoa/AppKit apps can take an rtf file to present in the app’s standard About window for credits/acknowledgments and if you want to present rich text with low hassle and resource consumption, by far the easiest way is to embed an NSTextView/UITextView with editing disabled which can then have a bundled rtf loaded into it trivially (just a couple lines of code).
A WebKit webview and HTML could be used instead in these instances, but that’s significantly more heavy and doesn’t have an OS-included WYSIWYG editor which makes it less friendly to e.g. non-technical team members whose job it might be to prepare the content being displayed.