To draw on some well-founded sci-fi concerns, the dark forest hypothesis would be that it is not a good idea to announce one's presence to the cosmos without preparation.
https://blog.usejournal.com/the-dark-forest-theory-of-the-un...
https://blog.usejournal.com/the-dark-forest-theory-of-the-un...
Yes we take the risk of stumbling on something so alien that it wouldn't perceive us as worthy of preserving, or that their means of communication could destroy us, but given the alternative is extinction anyway, it's worth a try.
And let's say we're long gone and no other specie picks up where we left off, at least we give a fighting chance to the other species of our planet to get rescued by something else.
> A civilization that wishes to continue expanding across the universe will need to compete for the limited resources with any other intelligent life
If a civilisation has the ability to travel across to different star systems, then going to war over a single planet’s resources makes little sense when they probably have the ability to manipulate and craft matter, at will, at the atomic level.