So Starfire is the only Teen Titan to not have a whole seasonal arc about her. 1st was Robin, 2nd was Terra, 3rd was Cyborg, 4th was Raven and 5th was Beast Boy. But Starfire never got one. But think about it. Did she even need an arc? She already had strong episodes about her like how she ended her sister in Betrothed and how she went through transformation in Transformation and how she dealt with racism in Troq. She already had strong individual episodes that dealt with strong topics. Did she even need an arc?
She didn’t have a seasonal arc, but she had strong episodes spaced throughout the show’s run, so her character was not ignored. Still, a season-wide arc with the Titans in space, teaming up with the Omega Men and fighting Blackfire, the Gordanians, and the Psions could have been cool.
I would have loved to see more centered around her but I agree with you, the strong episodes that featured her were enough to expand on her characterization. I also wonder if they didn’t give too much detail into her backstory because Teen Titans was aimed at a preteen/teenage audience (I think) and to keep it true to the comics, that might not have exactly been audience friendly? Either way, I like how they integrated details about her across episodes.