That’s why you're always looking for different ways to extract more information. Whether it is from the client, your users or your users behavior when you’re not actively engaged with them. I’m talking about all kinds of analytics: 'When do they log in?' ‘How long are they active?’ ‘What are the main actions my application supports?’ ‘Do the users think this as well?’ and so on.
You’re constantly exploring new ways to get more information about your user: Attending live sessions, feedback moments, do a segmented user survey, drive A/B testing to obtain better clickthrough rates and so on.
Best advice for any product owner? Unjudgementally absorb all information so you might find a chance to fundamentally change something for the good of all involved.