Sometimes all you need is just a simple static web page: instructions, a landing page, a collection of links. I think I have a perfect use case for Sway. Consider a scenario similar to what Laura Kokkarinen writes in her blog post:
How to build a guest user self-service registration for office 365 with azure An external user invitation needs an inviteRedirectUrl. Usually it is myapps.microsoft.com. In Laura’s case it was a given extranet url.