All Milestones are important. Milestones provide a roadmap of development from new borne forward. Milestone acquisition is really throughout all of life, even as adults. Children with developmental delay consistanetly demonstrate a pattern of disruptio in their milestones.
This list is not a complete list. A complete list would be voluminous. However, the consistent disruptions that I have noticed over the last 28 years are identified here.
“If the milestones are NOT met then your child is adapting at a cost.”