Suggest why Phenol is more reactive than Benzene in Electrophillic Substitution

With phenol, the oxygen atom is directly attached to the delocolised pi system in phenol, as a result the lone pair on this oxygen is incorporated into this delocolised pi system in phenol, increasing it's electron density.Therefore making it more susceptible to electrophillic attack, where the electrophile (which is electron deffiecient, is attracted to high areas of electron density. Whereas the delocolised pi system in benzene is not as electron rich, and is less suseptible to electrophillic attack, and substitution goes at a much slower rate