Consider the workflow that is stored in an SCM

    node('master') {
        wrap([$class: 'TimestamperBuildWrapper']) {
            sh 'echo I woz here'
        }
    }

if you view ${JOB_URL}/${BUILD_ID}/console

then you will see timestamps for the echo step but not the SCM checkout.

However if you view the logs for the individual step ${JOB_URL}/${BUILD_ID}/execution/node/3/log/ then the output is shown without any timestamps. This means that to check performance of an individual step you need to look at all of the logs which is a performance issue - and not user friendly.