A dummy is an easily available object that doesn't require any preparation, unlike bottles. Its use has become widespread over the last 20 years, with around 70% of babies now using a dummy at some point.
Even so, a dummy isn't necessarily the magic solution for calming a baby's anxieties. Too often, as soon as a baby starts crying or shows the slightest signs of being in a bad mood, he's given his dummy. The result is that it quickly becomes impossible for the child to cope without it, and it creates a need for the dummy.