The advice is sound, IMO. Fine arts teach in this way and it’s an accepted best practice.

The approach is reductionist and aims for solving the right problems first. You can reach for color, typography, etc after you’ve done the legwork to know your design satisfies basic constraints. It’s hard for me to generalize the statement, but learning to design this way (BFA at a well-known fine arts college) had an immediate positive effect on the usability of my apps and readability of print media. I still use the technique today.