It is not, but a write amplification of 36704:1 is one hell of an exploitable surface.
With that same Raspberry Pi and a single 1gbit connection you could also do 333333 post requests of 3 KB in a single second made on fake accounts with preferably a fake follower on a lot of fediverse instances. That would result in those fediverse servers theoretically requesting 333333 * 114MB = ~38Gigabyte/s. At least for as long as you can keep posting new posts for a few minutes and the servers hosting still have bandwidth. DDosing with a 'botnet' of fediverse servers/accounts made easy!
I'm actually surprised it hasn't been tried yet now that I think about it...
But the Dutch state instance isn't meant to assert power over user content nor is it meant to influence any information shared. Normal people won't be able to create an account on that instance, so they cannot see what people view or limit what people create.
The reason for the instance is to have a government owned instance to share things that aren't limited by another 3rd party commercial company. Now the government is in control instead of meta or Twitter and they can't decide to, for instance, limit view access for everyone with no accounts one day. (Looking at you Twitter)
Another additional advantage is that all the official dutch government accounts are now grouped on an instance with limited and screened account creation. So now everything from that instance is verified to be from the Dutch government. Possibly reducing fraud and impersonating accounts in the future once people get used to the federated usernames.