Should have expected it from the Sun, but the title is just clickbait and not even supported by the rest of the article, let alone the study.

Questions were about the various ways a phone can be helpful in parenting. Parents rated it as very helpful, so they might say that, metaphorically, they wouldn't know how to parent without one.

There is no indication that this is anywhere meant literally.

There is a big difference between relying on the phone to find information and using it as a baby sitter. This "study" seems to mash both when it helps with the narrative.

That's a bit like saying half of the parents in 1980 have no idea how to raise their kids without books.

It may be true, but it doesn't say much about parents or parenting.