nit: document.applets is not the same as the <applet> tag.

    Note: Support for the <applet> element has been removed by all browsers. Therefore, calling document.applets always returns an empty collection.

https://developer.mozilla.org/en-US/docs/Web/API/Document/ap...

For instance: https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Rel...

    The <applet> element has been removed (Firefox bug 1279218).

Also see https://github.com/mdn/content/pull/26850 which removed MDN docs for the element a couple years back, citing removals from major browsers.

<font> and <frameset> are still implemented in browsers, though, even if they are fully deprecated and marked by WHATWG as obsolete and non-conforming: https://html.spec.whatwg.org/multipage/obsolete.html#non-con...