Just a ping from four light years away does not seem worth the effort to me, it seems just slightly above throwing a rock in the direction of Proxima Centauri. At least take a picture.
By the way, there is also a thing called wait calculation [1] which deals with this very problem, when should you start an interstellar journey. There is not much of a point to start today if you can cut the travel time in half in, say, a hundred years since you would pretty quickly overtake the mission started today and arrive first despite the fact that you started a hundred years later.
> Just a ping from four light years away does not seem worth the effort to me,
That's all Sputnik was, a ping in orbit. But it was worth doing to get something, anything at all, in orbit. Sputnik itself wasn't important, but the knowledge and experience gained was.
You don't not throw a Sputnik up because you know that decades later you'll have the ability to throw up a space station. Sputnik is part of the space station process.
By the way, there is also a thing called wait calculation [1] which deals with this very problem, when should you start an interstellar journey. There is not much of a point to start today if you can cut the travel time in half in, say, a hundred years since you would pretty quickly overtake the mission started today and arrive first despite the fact that you started a hundred years later.
[1] https://en.wikipedia.org/wiki/Wait_Calculation