An early product does not need to solve every future problem. It needs to solve one meaningful problem well enough that someone can use it and tell you what is missing.
Write down the core journey from start to finish. Keep the features that make that journey possible. Put the rest in a separate list with the question each feature is meant to answer.
Define what you need to learn before release. That could be whether people finish the task, understand the interface or return to use it again. Choose measurement that respects their privacy.
A smaller scope also creates room for accessibility, loading performance and error states. Those details are part of a usable first release.