In theory. In practice, there are enough cases where it can kind of display, but things get lost. See your example above: The correct display already depends on the fonts being available locally. Which might be less probable for Baskerville or Menlo on Linux ;-). Not to mention that “WYSIWYG” makes little sense in the context of the Web: browsers come in all sizes, users have all kinds of preferences re fonts and their sizes, light/dark mode etc
And the advantage of a formatted note including images relies on them being included via data URLs. Which makes the files potentially huge and editing them challenging. As to the portability, see the last post in this thread: HTML code failure in DTTG with Formatted Note
Ah well. The time of silver bullets is long past, I guess. (Word, btw, is nowadays pretty much cross-platform, given that Pages and LibreOffice et al can read and write that format).
Disclaimer: Everybody can use whatever they want, imo. They should just be aware of the (dis-)advantages of their choice. Expecting that an HTML-based format can be anything close to WYSIWYG might lead to frustration. WYSIWYG on paper is easy. In a browser – not so much.