[Little Ray]

It would be very sad if it were really Dyson Sphere.
It would mean that there really is no way to cheat the speed of light, or even do effective STL travel, and that we are forever confined to a single system.

[who_would_fardels_bear]

There are two reasons a civilization would create a Dyson Sphere: to collect energy to supply the civilization and to hide from other menacing civilizations.

The existence of Dyson Spheres could mean that this civilization knows there are baddies out there that can come get them and want to hide.