SEO requirements for Hreflang make this an important use case, and I
hope Adobe Experience team looks at this. To augment what Jeff wrote,
HTML hreflang is a challenge to do sitewide (not to mention it's
additional html on a page) This is a quick guide about how to build an
XML sitemap with hreflang tags, but this is not specific to a CMS, and
AEM doesn't appear to have documentation on this:
https://ahrefs.com/blog/hreflang-tags/