If you block the packets, people will just use a VPN.
The best you can hope for is something like the Great Firewall, which only works on normies.
In this scenario your VPNs would still need to find a ISP that would let them route packets out of that country. This means that instead of a legit VPN company you have to deal with cyber criminals to get such a VPN.
Sure, ultimately technical/knowledgeable people will be able to get around it. But preventing normies from accessing Anna's Archive is what they care about, because most people are normies.