@jimLL
html is a
component of EPUB.
Your
complaint is like expecting the chips that were soldered on to the Motherboard to still be just 'chips' afterwards. They are not, they are now part of something bigger (and hopefully better).
Why are you not complaining about being able to save as a JPG? You can add Pictures to your Sigil EPUB.
Notepad++ is a Free HTML (and other)
code editor if you need one.
I was never satisfied with the WYSIWYG editors when I started playing with HTML(3), and never bothered since, to try and use them for my main editing mode. Sigil allow me to (mostly) check

my work and is a convenient way to break or join paragraphs. For all else, I usually work in CV.