After finishing Phantom Liberty and being on my 15th run of Fallout New Vegas, a lantern has lightened in my head about both games and the theme of letting go.

I would first need to credit Lyle Shnub on YouTube and his amazing video regarding Fallout New Vegas's aspect of Letting Go, which can be watched here.
There will be spoilers for Cyberpunk 2077's Phantom Liberty ending, and Fallout New Vegas, you have been warned.

In Phantom Liberty, V is offered a job by Songbird to get the Relic and Johnny Silverhand out of her head. As we all know, V's life changed after Konpeki Plaza and the game is about V shooting their way up to achieve "normal life", a metaphorical white whale for our protagonist to chase by various means, be it through selling their soul to Arasaka, run away with the Aldecaldos in hope of a cure, stage a heist for Mr. Blue Eyes, help NUSA capture Songbird in turn for a cure, or simply end it all with a singular gun shot.

We can also turn in Songbird for the cure, but nonetheless V is fucked, getting yanked by 2 gonks all because they couldn't let go.

In New Vegas, the courier meets the Think Tank, who cannot let go of their obsession with scientific experiences, regardless of how it affects the wasteland(see Cazadores), House's obsession with taking over New Vegas, Father Elijah's obsession with the Sierra Madre, the Sierra Madre, with itself.
All of those individuals and organizations, cannot let go of the past or their ideal future, thinking once they achieve X, things will be different. Father Elijah thinks that once he unlocks the Vault, he'll fix the Mojave. When Johnny nukes Arasaka, he thinks it'll help but in the end, both of these lead to the demise of those 2 individuals. Who could not let go of their ideals?

And now with V, regardless of the ending that the player chooses V never attains the "normal life" they desired so much. Whether you side with NUSA or ride with the Aldelcaldos, you are damaged and hurt due to not letting go of the past and not letting go of an idealized outcome.
Both the Courier and V "cheat death", but they never go back to how things were and the events they helped set in the end fucks everybody else in the end.
Whether you are a resident of Goodspring evading NCR taxes or Judy, having to live with her V dying in 6 months.
The conclusion is? Let it go because you cannot begin again.