Carl Sagan would likely tell you that the shared reality we all live in with each other still matters. In fact, it’s the only thing that matters, and all that the vastness of the universe does is remind us to keep this shared reality organized in a way that makes it more bearable.
Set out to do good work. Set out to be fair in your dealings with customers, employees, and reality. Leave a lasting impressions on the people you touch, and worry less (or not at all!) about changing the world. Chances are you won’t, and if you do, it’s not going to be because you said you would.