Lemmygrad can't be banned - first of all it's all federated. Even if lemmygrad stopped existing, every post that's federated on the dozens of instance we are linked with would still be up. You can't take down the federated web unless you take down every single federated website. Moreover, lemmygrad is self-hosted. Being self-hosted, the website can also be brought back very quickly. This is the case for any self-hosted website if you run daily backups like you should be doing anyway.
Independently hosted Internet communities like Lemmygrad are in a much better place than communities which exist as "guests" on corporate platforms like Reddit or Facebook, but we need to be thoughtful about this. This is not a problem which can be solved simply by renting dozens of VPSs. The Internet is not magic. It is composed of data centers, routing hubs, high capacity back-bones, last mile ISPs. The vast majority of the network is privately owned. Many aspects of the network are totally monopolized. There are many ways control can be exerted over it. As ecosystems like the Fediverse continue to grow, we will see this power exerted in new and unprecedented ways. Always be prepared.