Can't get the real site title as an anonymous user

Currently, there doesn't seem to be an out-the-box way of querying the site title. I ran some queries agains the site root with Volto, Plone 6 classic and Plone 5.2 and got the following results:

Querying the plone.site_title configuration registry record in any version gives me the correct value, however this requires permissions beyond that of an anonymous user.
Querying the volto demo (https://volto.kitconcept.com/++api++) results in the title of the content used as the default view of the site root as the title for the site object. In this example, the title is Welcome to Volto!
Querying the Plone 6 classic demo (https://demo-latest-plone6.plone.org/en) gives the same result as querying volto through ++api++.
Querying the Plone 5 demo (https://demo.plone.org/) site results in what I assume is the Zope site ID being returned as the site ID. In this instance, the value is Website. The Site title in the control panel is set to demo.plone.org, which is reflected in the plone.site_title record.

I asked this question on the Plone forum recently, and while I was suggested an addon (cusy.restapi.info) to be able to get the 'real' site title, it seems this functionality should be included in the core REST API.

https://github.com/plone/plone.restapi/blob/49cc786159acb2d152117aa77d8511a97345c630/src/plone/restapi/serializer/site.py#L65

plone / plone.restapi

Can't get the real site title as an anonymous user #1415