SharePoint in itself can be set up as a Document Management System, and a darn good one because of how configurable it is. However, without hiring a (very) expensive SharePoint developer to build a nicer user interface, your users won’t have much fun navigating and managing SharePoint.
There are however, alternatives. SuiteFiles for example, leverages the features in SharePoint that makes it a great Document Management System, but rewrites the interface so it’s easy to use. There’s also a bunch of plugins that extend the use of SharePoint and integrate it into your other Office applications like Outlook, and even add some cool features like automation.
While SuiteFiles has a heavy amount of integration with Xero, it’s not just for accountants; and is used by lawyers, engineers, healthcare providers and a variety of other professionals that want a powerful Document Management System that can look after all their documents.