What is the problem this feature would solve?

There is no way to programatically toggle telemetry on/off via an argument passed to the plugin.

What is the feature you are proposing to solve the problem?

In other plugins, there is an enabled param. Just add the same thing.

const TELEMETRY_ENABLED = false

server.use(
      opentelemetry({
           enabled: TELEMETRY_ENABLED
      })
)

What alternatives have you considered?

 if (TELEMETRY_ENABLED) {
    server.use(
      opentelemetry({})
    )
}