The correct answer is Vendor lock in. This option names a drawback and not a benefit, so it is the one that would not be a benefit of moving applications to a cloud native architecture on a Kubernetes cluster.

Kubernetes and cloud native practices are designed to increase portability and reduce dependence on any single cloud provider. Containers, standard APIs, and open tooling make it easier to move workloads between environments, and continuous delivery patterns and infrastructure as code reduce coupling to provider specific features. For that reason vendor lock in is not a benefit and is the correct choice as the undesirable outcome.

Faster release cycles and deployment velocity is incorrect because moving to a cloud native architecture on Kubernetes typically enables faster, more frequent releases. Declarative manifests, rolling updates, health checks, and integration with CI CD pipelines all increase deployment velocity and reduce release risk.

Cloud Run is incorrect because it is a managed serverless product rather than a disadvantage. It is related to running containerized workloads and can complement cloud native approaches, so it is not the right choice when the question asks for something that would not be a benefit.

Improved fault tolerance and uptime is incorrect because Kubernetes provides primitives for replication, automatic restarts, self healing, and load balancing. Those features directly contribute to improved fault tolerance and higher availability when applications are designed for cloud native operation.

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