We like the <i> tag for brevity and for the fact that most folks are using <em></em> for emphasized/italicized semantic text these days. If that’s not your cup of tea, using a <span> is more semantically correct.
> represents a range of text that is set off from the normal text for some reason. Some examples include technical terms, foreign language phrases, or fictional character thoughts. It is typically displayed in italic type.
Typically, but doesn't have to be. It's just about stuff that's set off, but not necessarily more or less important, "just different" I would say.
> is used to draw the reader's attention to the element's contents, which are not otherwise granted special importance. [..] However, you should not use <b> for styling text; instead, you should use the CSS font-weight property to create boldface text, or the <strong> element to indicate that text is of special importance.
Okay, to be perfectly honest, I can't think of a good example for something I would want to draw attention to without considering it more important. Maybe the names of persons in a news story? Hmmm. I don't know, but notice making something blink is a perfect and sensible way to draw attention to it... so the blink tag never went away, it just got shorter, so we can use it more liberally.
> The HTML Strong Importance Element (<strong>) indicates that its contents have strong importance, seriousness, or urgency.
So basically, this means flashing text in various bright colors while changing size rapidly. I know how to read standards, so nobody even pretend it could be otherwise; let's just fix our websites accordingly. A "call to action" with a big green button is way too tame, if it doesn't trigger a primal survival reaction, you might lose the client.