Apocalypse, Trips Back and Forth to Earth (Where I'm the Last One Left), High Tech, No Goody-Two-Shoes

Looking for books similar to 7 Billion People Transmigrated to the Apocalypse, but I’m the Only One Who Can Return to Earth. I’ll say it: there isn’t a single good book. If you disagree, throw a title at me. Time travel back and forth, high-tech support for the mission-driven plot, and a protagonist with clear goals who acts decisively. The first one focuses more on individual survival.