If you don't have any, log user actions when they succeed or fail to do something. Even a simple log can tell you many things.
It also tells you if they're failing to discover or use a certain feature, or if they're using something in an unintended way.
You can set up Slack channels for your product to help users troubleshoot issues. We have workspaces where users can get help. Whenever the 20th user complains about something, what to do next becomes clear. We tend to focus on issues with high frequency and high severity as opposed to say stylesheets, but it's because the field is struggling not for lack of good CSS. But it may be different for you and you may have a product where the value of the product is the better interface. Adjust accordingly.
- [0]: https://posthog.com/