The age that a child should stop wearing pull ups is between 3 years to 4 years of age or when they no longer need the pull ups.
Most children need to wear pull ups during the day while potty training until 2 to 3 years of age and some children may need to wear pull ups during the day until age 4.
And some children need to wear pull ups or diapers at night until age 5 to 8 years old or longer depending on how long they wet the bed.
The majority of children are potty trained by 18 months to 3 years of age and stop wearing diapers then and other kids are not fully out of diapers and potty trained until the age of 4 or near 5 years old.
Pull Ups do delay potty training in most kids as Pull Ups feel like a diaper as they are just pull up diapers that absorb the pee.
Most kids that wear pull ups when potty training take longer to potty train and the best way to potty train a child is to use regular underwear so the child feels the wetness and has the motivation to go pee.
With a pull up the pee is absorbed and they don't feel wet so they use the pull up like a diaper.
A pull up is good for when out of the house until they learn to hold their pee long enough or poop to avoid wet or poop pants.
For some toddlers pull ups can hinder potty training while for others pull ups can help potty training.
Pull Ups can feel like diapers because in reality pull ups are just pull on style diapers although they are less absorbent.
If a toddler is wearing pull ups and pees in them then they won't feel wet like they would when wearing underwear.
Just like a diaper the pull up absorbs the pee and so the toddler does not feel wet.
But if the toddler is wearing underwear then they will feel the wetness on their underwear which makes them feel uncomfortable and so they would want to use the toilet.
However some kids do potty train just fine with pull ups and they are good for when away from home to catch any pee or poop.
At home though its best to keep the toddler in underwear.