You can try to exercise, you can try to eat well, but no matter what you do, Final Fantasy 15 will probably outlive you. Square Enix has released reams of supplemental Final Fantasy 15 content since the game first launched in November 2016, and we'll soon be able to add a new mobile MMORPG to the stack.
I use the term "we" loosely, since there's no word if a Western localization is planned. Japanese game site Game's Talk posted about the upcoming game (thanks to SiliconEra for the translation), which is being developed by South Korean studio JSC Games. It's being published by China-based Shanghai Oriental Pearl Group.
The yet-unnamed mobile MMORPG takes place in a parallel world of Final Fantasy 15 and encourages players to fight together. "Parallel world" might be code for "Don't expect to see Noctis, Ignis, or the rest of the Final Fantasy 15's famous boys in the game." We obviously won't know who gets a cameo and who doesn't until the MMORPG comes out, but we don't have a release window yet. A trailer should be coming soon, however.
I joke about Final Fantasy 15 outliving humanity, cockroaches, and oxygen, but the deluge of post-release content has dried up considerably since director Hajime left Square Enix in late 2018. All planned DLC was cancelled with his departure. The upcoming book Final Fantasy 15: The Dawn of the Future will reveal what was planned for the DLC, however. Look for it this June.