So it is swings and roundabouts, heavy watering and no cutting or vice-versa. Of course, the ideal scenario would be just enough rain to keep the beds and borders going, but not so much that the grass grows too quickly. Much time can be wasted during summer in dead-heading, but at least the benefits are immediately apparent, like painting a window frame. The worst plants to deal with are perennial Geraniums because of the vast number of flowers that only last a couple of days before producing the familiar crane's bill shaped pods. Pelargoniums are no problem because the heads snap off easily at the base of the stalk, although there are always some unopened florets left on the discarded flower.
Roses have to be the easiest plants of the lot to dead-head.
The flowers are usually easily accessible and the plant really benefits from regular attention. Some plants of course are not really worth dead-heading, like annual Gypsophila and annual Alyssum, and others don't need it at all. There is a lot to be said for foliage plants in this respect, as long as they do not bear flowers that require removing because they detract from the foliage. Coleus, for example, have superb leaves but the flowers do need to go. During a drought there is the bonus of reduced weeding, another job that can account for an inordinate amount of the time spent in the garden.