How do you determine what digital software product to build next?

This is why there is a product development cycle, so that you can work on numerous projects simultaneously.

Typically, none of the things you intend to construct will work.

Consequently, you must establish a procedure within your organization for rapidly developing products, testing their viability, and iterating from there.

It is more important to have a strategically capable team that can produce MVPs rapidly and measure the results (user feedback/research) than it is to be a futurist.

Yes, you need a visionary to see the broad picture/long-term horizon. For the short-term (3 months), you need a process that requires rapid iteration rather than attempting to hit the home run and only releasing anything once it is flawless.