I think iframes are well worth looking into for embedding content. Despite the notion that some web developers think they should be deprecated, they have some unforeseen benefits especially for supporting media types.
I discovered an strange browser behaviour with supposedly unsupported video formats that I shared here: https://moodle.org/mod/forum/discuss.php?d=232352
They're good for all kinds of objects and there are loads of iframe plugins for Wordpress.
Another thing is that iframes allow for W3C.org compliant object and media embed methods that require Javascript to run in the head section of the page. The way that Moodle's page rendering works, it makes many JS embed methods ugly, hacky, and/or unworkable.