For me, the point is not constant active monitoring but being able to see when some application runs away with my system resources. At a glance network monitor

For me, the point is not constant active monitoring but being able to see when some application runs away with my system resources. At a glance network monitoring is also very handy — I can check if an application is absolutely chewing through data (or quietly not actually doing anything at all), which is quite useful for metered connections.