bold, italics, etc. are used to indicate context

How can you guarantee they are? There are no technical restrictions or instructions on how much or where you can use emphasis and strong emphasis in your message. Until that’s not the case, “italic” and “bold” should be treated as purely presentational markup.

used for accessibility purposes

Screen readers do not and should not care about presentation; abusing semantic markup to indicate through emphasis that something is italic or bold is anti-accessibility.

https://archive.today/2025.10.09-163824/https://techtrenches.substack.com/p/the-great-software-quality-collapse

Interesting fact: Firefox (or Gecko to be accurate, because there was no single “Firefox” browser back then - there was Netscape Navigator and Mozilla Application Suite) had such rendering mode, but it was quickly abandoned.[1]

1. https://hsivonen.fi/doctype/: “In the summer of 2000 before Netscape 6 was released, Gecko actually had parser modes that enforced HTML syntax rules and one of these modes was called the “Strict DTD”. These modes were incompatible with existing Web content and were abandoned.”