Interstellar flight is pretty hard, but yeah, who know how many asteroids there could be in our solar system that are from other solar systems BY DESIGN!!!
It could be the drive to colonize a new world dies off as soon as a race gets accustomed to living in a sub light hollowed out asteroid....???
So instead of colonizing they would just want to visit and explore and go back to the their hollowed out home atseroid and they would possibly spread to other asteroids.
If they can manipulate gravity they can manipulate spacetime and if they can do that then FTL insterstellar flight is a likely possibility.
It’s all quite fascinating...
Makes sense. They have a home, and one to which their physiology has necessarily adapted. Their eyes could be used to the permanent twilight of deep space, their muscles and bones are used to low gravity.
Every planet is a "gravity well" requiring massive amounts of energy to escape. Could be their resources are too limited to want to spend them on large scale travel down and up from the gravity wells they wish to explore/exploit.