Most practical purposes, particularly on laptops, are intermittent bursts rather than than steady-state. High short-term boosts give excellent practical performance benefits there, as your primary metric is task completion time (i.e. 'responsiveness').The problem here is thermals. Intel can get away with high thermals on a desktop, but not so in a laptop. Especially when people expects slimmer laptop chassis while maintaining high performance. The supposed “up to 5Ghz” is more like a rare boost, which will not benefit a sustained CPU heavy workload. So these are more like marketing and of any practical purpose.