Phantom Liberty’s most devastating moment is not in its action sequences — it is in the choice at the end of the Cynosure mission, where V must decide whether to leave Reed to die or save him at personal cost. Both choices have consequences, but the Reed survival path leads to an ending that changes the base game’s options permanently.
If Reed survives and you take him up on his offer, V undergoes a procedure that removes Johnny Silverhand from their neural tissue — resolving the base game’s central problem. V survives. Johnny is gone. The procedure also removes the Relic’s enhancements, leaving V alive but diminished and abandoned in Night City by Songbird, who takes the position she was promised.
The ending is the only one in the base game or DLC where V definitively survives without Johnny — but it is also the ending where V is most alone. No Johnny. No Rogue. No Panam. The city V returns to has moved on. The post-credits message from Reed is a bureaucratic form letter thanking V for their service to the FIA.
Phantom Liberty’s writers confirmed that the Reed ending was designed as a commentary on institutional promises: the system offers V exactly what they wanted and then provides it in a way that empties the meaning from the offer. V gets to live. Everything that made life meaningful was the price.

Currently on my first run and now I have to go back and look for this. Worth the detour.
Found this by accident on my third run. Came here to understand what I was actually looking at. Great write-up.