That's what I've included in my own HN Stylus stylesheet for years. Works on Desktop or Firefox/Android, but other mobile browsers don't support it, for lack of extension support.
Updating the HN markup to offer true blockquote support would be a more complete, though less trivial, solution.
I've suggested the first myself repeatedly.
pg asked how to fix this, and was given the solution, on HN, nine years ago:
Make groups of `/^\s+> /` lines turn into a `<blockquote>`. Render it slightly indented and italicized.
I don't think the major problem is that `/^ {4}/` lines don't wrap in a way that's useful for quotes; it's that there's no way to format quotes so people use the only formatting element HN has.
> I don't think the major problem is that `/^ {4}/` lines don't wrap in a way that's useful for quotes; it's that there's no way to format quotes so people use the only formatting element HN has.
It is a standing convention to use the following syntax for quotes here:
