The Fast Saga has a history of underusing some characters, but Fast X utterly failed Jordana Brewster's Mia Toretto after doing so much to redeem the character in F9. Aside from Vin Diesel and Michelle Rodriguez, Brewster is the only other actor who has remained a crucial member of the "Fast Family" since the franchise launched in 2001. As the sister of Diesel's Dominic Toretto, she was always involved in the conflict, but her role grew after becoming romantically involved with Brian O'Conner (Paul Walker). Even if Mia wasn't directly involved in whatever Dom and his crew were up to, she and her kids had a target on their backs.

https://screenrant.com/fast-x-jordana-brewster-mia-fails-after-f9-redemption/