Age of "Don't do it yourself" (blog.rybarix.com)

In some cases, there is risk to doing it yourself (rolling your own authentication scheme). But from a pure learning standpoint, yes people should be encouraged to build even if solutions exist. Perhaps there is a better version we don't know about until it's built.

When it comes to a startup or company project though, it also depends on how much time you spend on something that isn't the core problem.