Support has a vastly different perspective on the software you make and how it works than you do, has insight into how users actually try to use your product, are often treated way worse than full time developers—not only will knowing and talking to them be functionally useful, but you should always be on the lookout for how you can help them in return, maybe by improving a tool they use to inspect user info or advocating for them to your management, or shouting them out whenever you can for their own promotion chase.