This is my biggest issues with all of the messages we keep sending out to space. By the time it gets to its destination, it will basically be indistinguishable from noise
20 light years is about the farthest useful communication can be established. The farther out things are the longer the round trip and thus the more likely we have already figured things out by the time we get their answer. It would still be interesting to get a response, but our (and we assume their) civilization is moving too fast for much knowledge sharing. Eventually with knowledge sharing you assume something is obvious that isn't and so you get another round trip. Watching an alien movie no matter who far away they are will be interesting (even if it is more a smell based or something that we don't think of)
There is no reason to think we will ever visit them, but we can do other things when they are close.
There are not many stars within 20 light years though. The Femi paradox doesn't exist at that distance, there just not enough stars to expect to find life that close.
if this is a real situation I wouldn't be asked. So use salt