Mind-bending ‘Hollow Pencil’ reduces wood and waste by almost 85% - Yanko Design

It looks quite clever. As a pencil user, I would gladly try a few of those if they were manufactured.

But this is not correct:

Pencils haven’t changed much in hundreds of years. They still come wrapped in wood with a graphite lead running along the center

For the casing, a lot pencils, most noticeably cheap ones, do not use wood for casing. It's recycled plastic or some stuff like that. Here in France, I think Bic is recycling plastic to create the casing of their low cost pencils and colored pencils, while making it look somewhat like wood. I would say Staedtler does it too for its real entry level pencils but I'm not sure.

Like paper, pencil is one of those innovations that has reached maturity (to not say 'perfection') but it doesn't mean there is not much research still going on. Exactly like with paper ;)