In the first season of Star Trek: The Next Generation, Marina Sirtis, who portrayed Counselor Deanna Troi, was often written out of episodes, mainly because the writers simply didn't know how to write for the half-Betazoid character who was empathic. If she could sense what was going on, that made it more difficult to write the story.
In a 2018 Star Trek Las Vegas panel [via Screenrant], Sirtis said that she knew her job was on the line, which led her to be very insecure during the first season. As it turns out, she had every reason to be as Majel Barrett Roddenberry told her later that Gene Roddenberry had decided there were too many women on the show and that while a doctor and a security chief were needed, a psychologist wasn't. Shortly after that conversation, Denise Crosby, who played the security chief Tasha Yar, expressed her desire to leave the series, which Sirtis believes saved her job.
"Majel [Roddenberry] told me. Majel told me for a fact. Years later, I confronted her, because we were very close [...] I said to Majel years later, ‘Majel, I was going to get fired, wasn’t I?’ And she said ‘yes, you were. Gene came home one day and said we have one too many women.' [...] You need a doctor, you need a security chief, you really don’t need a psychologist. And it was when Denise [Crosby], Denise had no clue, but when Denise left the show, she saved my job."Marina Sirtis
On top of Crosby leaving, Gates McFadden was asked not to return to the show for the second season which left Sirtis as the only remaining female character until Diana Muldaur came onboard as Dr. Pulaski. It was only then that Sirtis was able to breathe easier.
Unfortunately, the writers for Star Trek: The Next Generation never really figured out how to write for Sirtis. But she got the chance to shine in the third season of Star Trek: Picard when showrunner Terry Matalas brought her back as a crucial character to the final season. In only a few short episodes, Sirtis became invaluable and proved Troi's importance as both an empath and a member of the crew.