There are algos which prioritize high fault tolerance and do so by increasing the number of leaders (or the minimum number of nodes that must have a copy of the lookup data).

One such algo is Chord:

https://en.m.wikipedia.org/wiki/Chord_(peer-to-peer)

It’s a peer-to-peer ring of nodes which have their values consistently hashed between them. The network leverages these things called “finger tables” which essentially store replication information in the form of a table. This table can have information which is incorrect or outdated and the peer you go to can tell you to go to another peer (usually the “next”/“successor”) until you find the value (or don’t).

Reason this algo can be used with no “leader” is because it can also work by just going to a node and doing a linear scan across all nodes. You don’t need a thumb table to speed up queries.