Thank you for this wonderful post. It definitely express how most of us feel about Triss.
Triss always felt that Geralt's relationship with Yennefer was toxic because of everything that's been happening between them. Them being on and off and the constant arguments about her infertility and him being sterile, leaving him before more than once, treating him like a dog, getting him and herself into troubles and being with other people knowing that it hurts him (Crach an Craite comes to mind) Triss always felt that he deserved better.
Despite the impression that most people get while playing The Witcher 3 (The people who didn't play the previous games nor read the books) Triss never took advantage of Geralt. If she did, she stated herself that she only did in bed. CDPR should've been careful approaching this one, because for the people who didn't didn't read the books nor played the previous games, it just sounds bad when tells Geralt in The Witcher 3 that she took advantage of him.
She was about to tell him about his past in The Witcher 1 and the events that happened during The Last Wish with Yennefer (Geralt told her that he's not ready to know about the past yet) that was the only reason Triss didn't tell him about it.
She helped him create a stable personality, she could've took advantage of him, tried to make turn him into the Geralt she wants. But she didn't, she told him that she doesn't want him to turn into her vision of Geralt's, she wanted him to reach that point by himself. She saved him more than once (Adda's kiss of death was the first thing I recalled)
The love letter after that was definitely a huge step up in their relationship. After Geralt went back to Vizima and talked to her about running away together, starting a new life and building a family was one of my favorite moments in their relationship.
The Witcher 2 events reinforced their relationship and it made it certain for most of us (Triss fans) that sacrificing for her will definitely have it's rewards.
Those rewards for those who stayed dedicated are yet to be seen.