None of the post-Destiny
books had or ended with "Everyone in the Federation has given up. Everything is gone to the dogs. No one is fighting to survive anymore."
They did have "Our heroes continue to work through these hard times, making the best of what they can. The civilian governments of surviving worlds are still functioning and strong and are helping everyone else to relocate and rebuild. Everyone's doing their bit. The Typhon Pact has been created but has not
engaged in any hostile act. We know of a race of xenophobic but benign beings called the Caeliar with a former Starfleet captain as one among them. The Borg are no more. The Titan is continuing its explorations of the Gum nebula. Voyager and a fleet of ships is going to the Delta Quadrant to explore and establish peaceful relations with the races there and to find out and make certain of the status of the Borg and Caeliar."
That's not hope enough for you after a large scale carnage?
Frankly given the scale of the devastation and the sheer numbers of displaced persons, there were so many more worse things the writers could have chosen to put in but didn't because its Trek. For eg. Losing the Peace
only had an almost
incident between Displaced Persons and the military of Pacifica, that could have been much more terrible given what we know about detention camps and such in our real world.