Substitute free to use and the statement still hold. I'm actually in favor of sites not specifying any fonts at all - only things like size, bold, italic. Let the user set a font preference in their web browser to something the find easy to read. No designer can say what is pleasing to everyone and never will. This whole thing is really just self gratification for designers.
That’s fine. It’s just a tick in Firefox to do so. Yesterday I made a readme intended for some Windows friends. Just a simple single html page. I set it to “Segoe UI”,sans-serif so it looks more like a Windows manual. If someone opens it on a mobile device or a Mac somehow, then it still looks fine. It mostly just avoids people seeing Times New Roman or Arial, which I don’t need A/B testing for to know is not as nice to look at or doesn’t look very Windows like.
Unless you use Chrome, you can also go to the reader mode to avoid all the CSS. Plenty of options for you!