Basically, the character had established herself as a crybaby and an obsessed fangirl for Sasuke, so much so that she said her aim in life was to ultimately be with Sasuke.
Of course, anime often features a pretty outdated and biased take on female characters, but Sakura came across as a shallow child whose life revolved around a boy. Moreover, it struck a nerve with the fan community when she criticized Naruto saying he is unruly because he is an orphan. And to Sasuke, no less.
However, what fans often fail to realize is that she is actually a depiction of the toxic obsession that people see around them in daily life. Moreover, Kishimoto gave her a huge helping of character development, which was astonishingly apt for her.
Sakura the "trash" kunoichi: does she deserve the hate she gets?
What fans fail to acknowledge is how far she has come over the course of Naruto and Naruto Shippuden. Sakura started out as a weak side character, who could do nothing more than ask for help in dire situations.
She had no elite lineage, no Kekkei Genkai like the Sharingan or the Byakugan, and yet she came a long way not only as a medical ninja, but also as one of the strongest kunoichi of Konoha.
She saved Kankuro by performing surgery and concocting an antidote for the extremely potent and unknown venom Sasori used. She then went on to defeat Sasori with the help of Granny Chiyo.
Above all, she could awaken the Byakugou 100-Healings Mark, a medical jutsu of Hashirama Senju that Tsunade passed on to her. Currently, Sakura and Tsunade are the only shinobi known to be capable of using it.
As for her feelings towards Sasuke, her childhood obsession compelled her at times to follow the dark path he has taken, but ultimately, she just wanted to stop him and bring him back to the village, much like Naruto.
Maybe she got stabbed right after rushing towards Madara, and maybe she isn't on the same power level as Sasuke or Naruto, but she is still undeniably powerful nonetheless.