Because people using default OS encodings didn't mark their html files with explicit encoding. And defaults were not utf-8 for a long time. For example notepad

Because people using default OS encodings didn't mark their html files with explicit encoding. And defaults were not utf-8 for a long time. For example notepad defaults to utf-8 only since 2019, lol. https://techcommunity.microsoft.com/t5/windows-10/windows-10-1903-how-to-change-default-encoding-utf-8-to-ansi-in/m-p/991268 https://techcommunity.microsoft.com/t5/windows-10/windows-10...