YugabyteDB has demonstrated superior scalability compared to Amazon Aurora PostgreSQL, with a 10x increase in throughput and nearly twice the write IOPS/sec, while maintaining comparable latency. YugabyteDB's distributed SQL architecture allows for horizontal scaling of writes, reads, connections, and transactions, making it more suitable for large-scale applications that require high performance and flexibility. In contrast, Amazon Aurora PostgreSQL has limitations on its scalability due to instance size constraints, which can lead to a bottleneck in write throughput and consistency. Additionally, YugabyteDB's cluster-aware JDBC drivers simplify the management of database connections and eliminate the need for load balancers, making it easier to scale applications. Overall, YugabyteDB appears to be a more scalable and flexible option for large-scale PostgreSQL-compatible databases.