JAJ

If parent has enough physical presence then child is automatically a USC anyway - no need for expedited naturalization.

Sometimes neither parent nor grandparent has enough physical presence, hence the need to look at getting child an immigrant visa for the child to become a USC that way.

LAL

If USC physical presence is after child's birth the child is not an automatic US Citizen - my husband had 6 years 11 months physical presence in US but because his parents divorced and he grew up in UK only 23 months were after he was 14 - from vacation time so our daughter did not meet the USC criteria, but after we went on vacation for 12 weeks to US he had the physical presence so we could apply for citizenship, had we not gone to the States we would have had to rely on the USC grandparent rule. Any other children we may have in the future will be automatic US Citizens though.

I suppose if someone with foreign parents was born in US then never lived there they would have to go the LPR route for their children, but in most cases there is a USC parent or USC grandparent that meets the physical presence criteria.

LAL