I don't think it's just about doing vs talking.

There are people who are great at something not because they do novel work, but because they redo known work that's really hard.

Not everyone has the luxury of knowing where the frontier lies and working at it. Many, many people reinvent the wheel simply because they don't know that what they're trying has already been done. And they can redo the work in a great way.

Of course they'll never get credit for this.