In the comic books? Nothing, I agree they totally have wasted him. In outside media though, it’s elevated his standing and it’s caused him to be featured more and more prominently. Plus have you seen how DC treats the Titans? What on Earth makes you think Cyborg would benefit from rejoining them? The recent Titans comics have been mediocre dreck that spun around in circles going nowhere. Dick got shot in the head and became Ric. Wally got Dido’d with HiC. Donna remains the complete mess she’s been since CoIE. Beast Boy and Raven have gotten zip to do. Starfire has ditched the Titans to join the JL as well, and I haven’t heard much about her and Vic interacting. Like what specific kind of interactions do you see Vic getting that would benefit him? Because just calling back to the NTT isn’t going to do squat, it didn’t help Wally or Dick for example.
And even on the Titans, Cyborg doesn’t get the same focus as Nightwing, Starfire, and Raven get.