Yes, but: writing code always teaches you something.

I've worked at founder-sized startups and $xxb dollar public companies. I've never read a product spec, a pitch deck, or a PRD that describes a solution that, if implemented in the way described, would solve the problem. Building the thing teaches you how it should behave.

Software is a complex, interactive medium. Iterating in the code, with people who understand the problem and care to see it solved, is the only way I've seen valuable products get created. Meetings and diagrams help, but it's not until you write some working software that you know whether you have something.