Wade Trimmer takes us through a reason why you might not want to use VPC endpoints to separate applications from distributed database platforms:
AWS PrivateLink (also known as a VPC endpoint) is a technology that allows the user to securely access services using a private IP address. It is not recommended to configure an AWS PrivateLink connection with Apache Kafka or Apache Cassandra mainly due to a single entry point problem. PrivateLink only exposes a single IP to the user and requires a load balancer between the user and the service. Realistically, the user would need to have an individual VPC endpoint per node, which is expensive and may not work.
Using PrivateLink, it is impossible by design to contact specific IPs within a VPC in the same way you can with VPC peering. VPC peering allows a connection between two VPCs, while PrivateLink publishes an endpoint that others can connect to from their own VPC.
Read on to understand how this affects platforms like Cassandra and Kafka.