I don’t understand the excitement around Headless WordPress. WP has a perfectly capable templating system – and now FSE. And I firmly believe that WordPress is actually wp-admin. I’ve seen and done cool things with the REST-API – like External Content Integration.
Now, there are situations where a headless approach makes sense. When WP is the admin for mobile app. It can also be a great approach for a site that has spiky traffic – decoupling frontend from admin provides the ability to cache in clever ways.
But, for most projects the baked in rendering in WP is sufficient.
I’m completely ignoring the cool and fun factor – for some projects that is justification enough to go headless. But, if it’s for a client it seems to me there are few situations where headless makes sense.