"Can this suggest that in our galaxy there is not a single civilization advanced enough to (or want to) modify Sagittarius A* in a significant way, or maybe bla

"Can this suggest that in our galaxy there is not a single civilization advanced enough to (or want to) modify Sagittarius A* in a significant way, or maybe black hole just cannot be influenced easily even for a higher tier civilization" It is also possible, that they don't want to modify the black hole, because it is working as intended? Why would we change the sun, even if we could? But apart from that, yes, a civilisation would need to bery very, very advanced to significantly alter a black hole, like the one at the center of our galaxy.