Does prioritizing your sleep actually help?

I know that sleep is the best thing for your body, and getting an adequate amount of sleep each night boosts cognitive function and whatnot.

Still, I'm nervous that targeting 8-9 hours of sleep each night would take away from the couple hours of studying/working that I could be doing.

A lot of my friends and people I see online, too, don't prioritize sleep such that they're getting 7+ hours, and they're doing fine academically.

I know that sleep is good. But, is it worth shaving off some study/work time just to sleep more?