What you may be missing from the history of email is that when it started, it was never about universal communication. It was internal communication within your own organization or between connected orgs. Frankly, it was a bit of a revolution when it started to be able to route outside your own network. And it wasn't always across the internet - while certainly IP-based email existed on the early networks, there were also modem-based email networks which were used by local communities and even for cross-organization email systems.

So unless you consider the entire population of a country to be a single organization, it makes little sense for them to have looked into running an email service.