It seems too low tech to be useful for any project of any complexity. Existing HTML template frameworks do a lot of things like character and syntax aware data escaping (and avoiding double-escaping), template caching, plugins, code generation, tag extension, filters, etc.
Other than being slightly more concise and appearing more functional, I don't see the benefit of this over something like Twig or Smarty. At some point you're going to wind up re implementing features that already exist in a framework anyway.
Low-tech is fine, however I'll assume your example has been excessively simplified for the sake of brievity because as-is it's prone to break your page.
You have the PHP business logic code as usual.
Then instead of doing
You have a view function that does that for you And then on the HTML markup, you place those calls as tag libraries in other similar frameworks, Very low tech, but does the job similar to JSP tag libraries and provides some organization.