I tried to stay away from points that would be spoilers.
The technology had control over gravity and demonstrations of the environments it created on display.
You’re going to argue a device drawing energy directly from black holes is limited in its scope of creation?
The progenitor said it could create life, not replacements of what was. It also said the scale and speed were up to the one managing the process.
They could have easily replaced any of the species that were wiped out. Not trying to argue for exact copies of books family, only the life forms and planets.
Only 20 light years? Say that to the life forms that stopped existing.