When I was last in school I struggled with "networking your way into a company" and wound up landing my internship (and ultimately full employment) on the one company who offered a test before the "Fly you out to meet us" step.
Imagine you're hiring someone to do your taxes. Sure, you'd expect them to use a calculator to do all the hard addition/subtraction, or more likely spreadsheets. But if you asked them to add 5 and 3, and they said "I would use a calculator, this is a stupid question, I can't just tell you off the top of my head" then you're probably not going to hire them.
It's a super basic test of 'Can this person code themselves out a paper bag."
being able to solve problems is more important than how you solve problems. (generally speaking, yes i know there are exceptions)