Pigeons are good at keeping the chicks out of the public eye until they’re fully fledged. Their nests are typically on high ledges, so, unlike nests in trees, they’re not easily seen from the ground.
Because pigeons are ground feeders, the chicks would be especially vulnerable to attack until they’re competent fliers. Until then, the parent provides room service in the form of a partially digested “milk”.
Unlike most other birds, fully-fledged juveniles of the pigeon and dove family look very much like adults. They don’t have distinguishing plumage and are similarly proportioned. Here’s a good picture of a pigeon chick that shows how they look well before they leave the nest.