ARIA and the web group define title to be used. [0][1] It's just that many agents just don't use it correctly. JAWS and NVDA do. Microsoft Speech used to ignore it, but I think they fixed that around Windows 11 release. I'm not sure about VoiceOver. Most braille readers I've used... Well, you'll be lucky if they read anything correctly.
With the three big ones, JAWS, NVDA and Speech using it correctly, I'm pretty happy guiding people to use it today.
> The title attribute represents advisory information for the element, such as would be appropriate for a tooltip. On a link, this could be the title or a description of the target resource; on an image, it could be the image credit or a description of the image; on a paragraph, it could be a footnote or commentary on the text; on a citation, it could be further information about the source; on interactive content, it could be a label for, or instructions for, use of the element; and so forth. The value is text.
[0] https://html.spec.whatwg.org/multipage/dom.html#the-title-at...
> Most host languages provide an attribute that could be used to name the element (e.g., the title attribute in HTML), yet this could present a browser tooltip. In the cases where DOM content or a tooltip is undesirable, authors MAY set the accessible name of the element using aria-label, if the element does not prohibit use of the attribute.
[1] https://w3c.github.io/aria/#aria-label
[2] NVDA bug confirming they use it: https://github.com/nvaccess/nvda/issues/7841
[3] Sorry for the numbers everywhere. I've got a footnote macro set for the way most HNers use this.