in the end, he got to the end (border) of the city (approximately near the orbit of Jupiter) and the fetus grew into a child in an unpolluted environment(because the authority (it's program with rigid logic) needs to make sure that there is no infection)).
And so the child on the last page is 7-10 years old, they are attacked by some creature that is not a guardian(because they are cruelly forbidden to attack people with network genes).
It is also clear from the epilogues(Blame!² and NSE: Net Sphere Engineer) that the main character released the race of silicon life into space.
It is also clear that the Saveguard no longer attack people but only passively defend their structures. Moreover, judging by the existence of the Dismantlers that the Authority sends, Saveguards are now suppressed by the Authority(this is possible only and only when the carrier of the network genes himself will say what the Authority needs to do(remember about rigid logic)).
This confirms that network genes have been activated in the net sphere. But the full details of the changes and reforms in the net sphere are unknown.
Results.
Enemies:
Silicon Life - Defeated and almost destroyed, they were then released into free space outside the megastructure.
Saveguard - Defeated and suppressed by Authority(Saveguards can't attack humans without network genes and can only defend themselves).
Neutral:
Builders - They stopped the endless growth of the city, judging by the epilogues, they serve the existing structures.
Friendly:
Authority - They have restored their function and are helping human civilizations in the layers of the city to develop again.
Killy - Victory. And obviously he's alive but we don't know what he's doing after activating network genes.
Humanity - Now can develop and judging by the sequel is in an early stage(So thinks the Authority, remember the crazy technology throughout the manga, Yes it's early stage)
Town - Has become less dangerous but still remains terrible, deserted and destroyed. The infection(!) has not gone away, as well as countless unintelligent silicon creatures, mutants and other things that threaten humanity without and with network genes.