I gave my youngest a dummy because she had silent reflux and it helped her. She had it whenever she wanted but when she started toddling around and she dropped it I would stick it in the kitchen drawer out of sight.
When she turned 2 she went through a phase of wanting it all the time so I let her walk about with it so it didnt become the attractive forbidden thing but again, if she left it lying around I put it in the drawer.
By the age of 3 she stopped bothering with it and after a couple of months left in the drawer I binned it/them.
In contrast, I wasn't given a dummy as a baby and tucked 2 fingers until I moved in with my boyfriend age 19.
My middle daughter didn't have a dummy nor sucked her thumb or fingers.
My eldest had a dummy which she was attached to but i gave it to the baby reindeer at xmas in exchange for a present. She then went on to suck her thumb and still does occasionally at 22 years old.
Basically...all kids have different sulking needs and it probably makes little difference whether you help them with it or not.
I'm 45 now and although my finger sucking ended age 19 I still twist up shoelaces (to stop me twisting my hair) and like fabric pressed against my upper lip when I'm relaxing. Anytime I try to just sit still I end up biting my nails/fidgeting/plaiting my hair etc.