Think pipeline of product opportunities, not a product backlog of to-do items. A pipeline is proactive. A backlog feels reactive.
Scrum.org defines a product backlog as an ordered list of what is needed to improve the product. However, people think of it in the dictionary definition, an accumulation of unperformed tasks, which has a negative connotation, as in a “backlog of court cases”.
On the other hand, a pipeline is defined as a channel and process of supply, as in “new vaccines in the pipeline”. Sales teams use “sales pipeline” to mean a visual representation of where all of your prospects are in the sales process.

A product opportunity pipeline is a funnel, not a tunnel.
Opportunities entering the pipeline may or may not be a “go” for product development. You have a pipeline of product opportunities, that go through several stages, such as: Problem Discovery; Problem Definition and whether it is worth solving now by us; Concepts and Validation; Opportunity Brief and Pre-release Notes & FAQ; Product Spec, Tech Design, Work Estimation, and Development; Releases; and Onboarding, Adoption, and Growth.
Top of the funnels is a “strategic reserve”.
When a product team has a product vision and a product strategy, it proactively prospects for problems to solve and opportunities to pursue. While the team may put items into a so-called backlog, it is not solely for perfect grooming. The product team deeply understands the customers’ or prospects’ jobs to be done. Such a backlog becomes a strategic reserve of market insights ready to be deployed for opportunities.
Measure the product opportunity pipeline
A pipeline can be managed using goal-setting techniques like OKRs. You can progressively invest more cross-functional effort as opportunities advance through the pipeline. Pipeline can be measured using metrics like pipeline size, quality, conversion rates by stage, velocity, opportunity win/loss, and opportunity value to cost, etc.
Think product pipeline, not product backlog.
PS: Check out more articles on building products. I write to pay it forward and to sharpen my thinking.