Absolutely, having a service that just listens on port 80 is so much simpler to reason about. I would also add a much easier development setup, as well as deployment to your list of advantages.
That said, having a Go service just be exposed to the wild wild internet may not be a smart idea. Take a look at this issue [1], it is perfectly clear that Go services (relying on net/http) still need babysitting by a competent reverse proxy. It is a case where Go's mantra about simplicity leads to leaky abstractions and just clearly immature solutions.
Also not talking about TLS certs, WAF and other concerns that also may bring nginx etc on board anyhow.