The page describes it in the middle by describing how you can encrypt your email and use that connected mail box with it.
This should allow you to actually send legal save communication to the government.
Actual electronic signatures recognized by law are not based on GPG.
Using your eID?
Do you know this or do you assume this?
GPG signatures convey no special legal status above regular email even if the key is signed by a government-owned company that verified your eID.
But let's see how it is currently reading this can become the defacto standard.
And technically it's a good workflow/choice
This would even allow companies to offer this for you because the only interface necessary is the key
I can envision a _lot_ of use cases for having your name publicly recognized by a trusted party.