Marvel killed off their most popular female character with Black Widow. Then Wanda became the most popular female character and they killed her off too. Even Gamora, who's never been at that level of popularity, was still well-liked and beloved but they killed her off too. The MCU hasn't had a good track record with their actresses returning. ScarJo probably won't ever come back after her lawsuit against Disney. Elizabeth Olsen has publicly stated that she wasn't happy with how they villainized Wanda. Zoe Saldana has also said she's done with franchises.
Ironic that with Carol, they're keeping her around, despite her headlining the world's biggest box office disaster. Even as someone who loves her in the comics, I have zero interest in her in the MCU.