That's a fair point. But did Mac have the same issue as Windows where file extensions were not shown by default? That feels like it would have been the core issue.
There is a "show all file name extensions" option in Finder, but I don't recall if it's on by default or not as I haven't had to set up a fresh macOS install in a while and I've always had it turned on.
But, macOS isn't like Windows - the file extension doesn't matter. I can have a "file.txt" but it's actually a .xlsx excel workbook, and Excel will open it just fine (albeit, with a warning that the file extension doesn't match but that's dependent on the application presenting a warning). Windows actually uses the file extension to determine the type, macOS (and other *nixes) don't, they'll use some other file metadata. You can put whatever extension you want on a file, it doesn't matter except for determining what default app will attempt to open it when double clicking it in Finder.
