Once a wearing schedule is approved by the US FDA, it costs time, money and
effort to go back and change the approval. Why would a lens company work
that hard to carve its market in half? Especially when they have new
products in the pipeline that will obsolete these lenses in just a few
years.

Many US doctors tacitly approve (it's called "off-label use") but experts
are gravitating toward the newer lenses.

-MT