Is the thin membrane of skin that connects from the floor of your mouth to your tongue's tip important and if not can you remove it to make the tongue stick out more or be more flexible?

A girl who used to be in my school had a medical case where her tongue was more or less attached to the floor of her mouth. The membrane was either too short or too rigid. But the doctors made her have it surgically removed because she couldn't speak clearly otherwise. I guess it allows your tongue to move around your mouth properly.