By most metrics, Batman is probably the most essential component of Gotham City. Without the Dark Knight's influence, the city would fall into chaos. Recently, however, some potential futures have nudged Bruce Wayne into the periphery.
In the past, there have been future tales that feature Bruce in a starring role. Most famously, Frank Miller, Klaus Janson and Lynn Varley's The Dark Knight Returns depicts a future where Bruce comes out of retirement to save Gotham City. Bruce may have retired for ten years before this, but when he returns, Batman takes center stage of the tale.
Even in futures like Batman Beyond, where Bruce is too old to don the old cape and cowl, he's still a pivotal part of Gotham's landscape. Not only does Bruce head up the board at Wayne Enterprises, but he's also crucial in training Terry McGinnis, the new Batman. Although both The Dark Knight Returns and Batman Beyond keep Bruce in the spotlight, recent tales depict Gotham's future from new perspectives.
"Future State" is a prime example of a Gotham City devoid of Bruce's influence. For one thing, Future State: The Next Batman #1, by John Ridley and Nick Derrington, introduces its titular Caped Crusader, who has almost no connection to Bruce Wayne. Tim "Jace" Fox, the son of Lucius Fox, becomes the new Batman. Jace isn't chosen or trained by Bruce, he just becomes the new Batman in order to fight the Magistrate, a privately funded police force.
Bruce, meanwhile, is revealed to have faked his death in Future State: Dark Detective #1, by Mariko Tamaki and Dan Mora. Bruce still secretly fights the Magistrate, making him an important figure in the shadows, but he's cut off from the rest of the Bat-Family. When Bruce and Jace meet in Future State: Dark Detective #3, by Mariko Tamaki and Dan Mora, they don't even recognize each other, demonstrating Bruce's background role in the future Bat-Family.
Additionally, Future State: Nightwing #1, by Andrew Constant and Nicola Scott, reveals Dick Grayson to be the Gotham Resistance leader. Nightwing even works with Jace to fight off the Magistrate. Another future, depicted in Batman/Catwoman #3, by Tom King and Clay Mann, features Bruce's daughter, Helena, as Batwoman. Bruce has died of cancer, leaving Helena to take up her father's mantle without his help. Working with Commissioner Dick Grayson of the GCPD, Helena fights crime in spite of Bruce's absence.
Even in Batman Beyond's future, Bruce has taken a step back from the spotlight. Batman Beyond #50, by Dan Jurgens and Sean Chen, sees the extended Bat-Family take on The Dark Knight's legacy. First and foremost, Terry McGinnis continues his career as Neo-Gotham's Batman, joining a future incarnation of the Justice League. Bruce, meanwhile, is still a supporting player, but his age and health have forced him to step back a bit.
Dick Grayson is also the father of a new Nightwing, Elainna. As the new Nightwing, Elainna upholds not just the legacy of Batman, but the entire Bat-Family. Barbara Gordon begins training the next Batwoman, while Damian Wayne is still around, using his resources as the new Ra's al Ghul for good.
There are several other potential futures without Bruce Wayne, including "The Batman of Bethlehem," as depicted in Batman #666, by Grant Morrison and Andy Kubert. In these potential futures, Bruce is either in a supporting role or absent entirely. All of these futures speak to the growing role of the Bat-Family. Ever-expanding over the decades, the Bat-Family is full of heroes willing to honor Bruce's legacy.
Dick Grayson, for example, could be the leader of the Gotham Resistance, the new Commissioner of the GCPD, or the proud father of the new Nightwing. Bruce has many children, both adoptive and biological, who could potentially carry on in his name.
Even those who aren't related to Bruce, such as Jace, could pick up where he left off. Jace has no real connection to Bruce Wayne, but he was inspired by the Bat-Symbol, wanting to be part of something greater. It's this symbol that has inspired the people of Gotham to maintain hope and fight for the future, just like Batman.