> Short of discovering a practical FTL (which seems likely to be impossible thanks to the Fermi Paradox) You could colonize the galaxy in few hundred million y

> Short of discovering a practical FTL (which seems likely to be impossible thanks to the Fermi Paradox) You could colonize the galaxy in few hundred million years at most without FTL. Replicating machines which can build and launch many more of themselves after reaching each new resource rich system is all that is needed. Humanity may not reach other systems, but either descendants of humanity or human derived machines improved over many generations during transit by AI(doesn’t have to be AGI) is likely to visit.