It’s extremely important.
I’m currently in a position where I don’t have an in-depth understanding of the product and I can feel it when it comes to brainstorming.
As our product is a B2B where our users are sysadmins I have no contact with clients or use of the product. I think it makes it much more difficult to understand what is needed.
Where I see some of my client facing colleagues are on the forefront of understanding what needs to be improved.