The city is a shell of what it was, and several major characters are either dead or absent so far.
Given that this is the Arrow-verse we’re talking about and three of the four shows have changed time on more than one occasion, there’s the question of whether this is a future that can be avoided.
Arrow’s flashbacks were never the most cheerful scenes of the series as they chronicled Oliver’s “years of hell,” and the flash-forwards have been even grimmer as they reveal a seemingly hopeless future for Star City.