Ehh. Gorilla glass is strong against impacts, dude was just trying to sell some extra products.

If you aren't dropping your phone directly on concrete or metal you're probably okay, but having even a well made slim case that gives a small lip around your screen will prevent direct impacts and spread the kinetic energy.

In my experience it was actually more common to break the back of a phone when it was during the glass fad, but now that we are back to metal backed phones that's a non issue.

Also, impact resistance is different than scratch resistance and both is not feasible without making the screen cost more than the phone.