My mother was very anti dummies. So, I did not use them for Nos. 1 or 2. However that second one - a girl, found her thumb, and continued to suck that for the next 16 years causing her teeth to be pushed out of shape. Only when she had a brace did she actually stop sucking that thumb.
As I fostered small babies, besides my own I soon discovered that some small babies really have such a strong sucking instinct that they are not happy unless they have something to suck. I happily used dummies (not those which could be filled with sugary drinks as even back then it was obvious that would cause early tooth decay). So, sometime the baby I had around would have a dummy and sometimes not. Once they were a year old I would encourage them only to have the dummy to go to sleep at night, and somewhere round 2 or 3 yrs it would be 'be donated' to a nursery!!!!
Do think it is so easy to be judgemental. As long as bubs and Mum are happy and well looked after what difference does it make if they do or do not have a dummy.