Not necessarily. The last two times I've broken the screen, the screen has been replaced. It can still be used with the broken screen, but the cracked glass can be a little hard on the ear when trying to make a call.
Someone (thankfully) recommended me to a place here in Adelaide that fixes the glass screens. Much cheaper than getting a new phone.
They know me by name now. I have loyalty card. When I break the fifth phone, I get it repaired free ;)
It works fine. I have my work calendar, which updates automatically to my phone, and I have all my Outlook mail folders on my phone as well. I can't fault it, but I'm not all that tech savvy.