The INTERNET is the hydra, the challenges are scale and credible exits. 

People really want/need great large "marketplaces" to coordinate and connect within. 

This results in the inevitable need for centralization in some/many aspects of serving data. 

There will always be a set of the largest and most popular chat apps, websites, and ... nostr relays which could be choked, and causr disruption.

The fact that servers can mirror data does not change this because, it would be impossible for many/all peers to serve extremely large data sets.

These are physical and incentive-locked dynamics that cannot be changed, but they can be mitigated at other levels (which nostr does not use afaik).

The good news is that end users CAN be protected from this, but the bad news is scaled servers will always have physical risks, despite scaled servers always being extremely useful.