Why good brands still start on paper
Brands benefit from starting on paper because sketches are quick and cheap to change, so a team can explore many ideas before committing to one. Digital tools work best after the direction is clear.
Polished too early is a trap
Design tools make everything look finished within minutes. That is useful later, but early on it is a trap. Once an idea looks polished, people stop questioning it and start adjusting the details.
The conversation moves from whether this is the right idea to whether the blue should be a little darker. Time goes into refining something that may be wrong.
What a sketch does better
A sketch on paper has the opposite effect. It is quick, it is cheap, and nobody is attached to it. You can try ten directions in the time one screen takes to build, and throw away nine of them without regret.
Sketches also invite comment. People who would hesitate to criticise a finished design will happily point at a rough drawing and say it is not quite right. That honesty is what you need at the start.
When to move to the screen
Move to the screen once you can explain the idea in one sentence and the people involved agree with it. At that point the digital work has a clear job: making a chosen idea sharp, consistent and ready to use everywhere your brand appears.