Bitcoin is slow because of the many servers not in spite of it. Because of the design of the network, all servers need to receive every transaction and servers need to be able to be pretty small, which limits the transaction rate.
Bigtable: https://cloud.google.com/bigtable/docs/replication-overview
> When using replication, reads and writes to the same cluster are consistent, and between different clusters, reads and writes are eventually consistent. If an instance does not use replication, Bigtable provides strong consistency, because all reads and writes are sent to the same cluster.
DynamoDB: https://docs.aws.amazon.com/amazondynamodb/latest/developerg...
> Both tables and LSIs provide two read consistency options: eventually consistent (default) and strongly consistent reads > Eventually consistent reads are half the cost of strongly consistent reads