In v1, one could setup Traefik to expose it's dashboard, api and ping, but the ping endpoint would not be subject to authentication.
In v2, I am unable to attach two services to the same router (api@internal, ping@internal) - and the middleware defined for authentication applies to the entire router; so even if I would get both services working on the same router, both would also be subject to authentication.
To be able to perform ping probes from several different regions (For instance PingDom). This way I can determine amongst others availability of my web application from Asia and the USA.