When I start this via the arguments I pass (well, any arguments),
without the service it starts and I can access the server.

The service never starts (and due to its simplistic nature, no
"BOOM CRASH THIS IS WHY I REFUSE TO START" is seen.
In this version I added 'networking' to requirements, still no change.

Anyone got an idea what could be missing from making this simple service
functional?

Patches appended.
-- 
https://pragmatique.xyz
PGP: https://people.pragmatique.xyz/ng0/