Status 200 is not a render
A database error page, a fatal error, a blank body and a directory listing are all HTTP 200.
When a migration finishes, somebody wants a green tick. The cheapest green tick is a status code, and the status code is the one thing that will be green whatever happened.
An application that cannot reach its database still answers. A template with an unhandled exception still answers. An empty document root still answers, sometimes with a helpful list of the files that are not there.
So assert on content. Assert the title matches. Assert the page carries a value that could only have come from the database. Assert every asset the page references returns 200 AND the right content type. And include a name you invented, that must 404, because a site that answers 200 to everything will answer 200 to your check too.