Basically I was ready to post a top ten about why I dont like Kusum anymore just for myself, but thanks to the recent videos I am saved this effort.
Kusum is willing to die rather than accept the fact that Saras was never hers. She isn't strong enough to go the Pramad route, which is obvious. But to expect her own sister to sacrifice it all in the wake of everything that happened is wrong.
Even if Saras had the tiniest bit of love for her as a romantic other, it would still be wrong. Because Kumud loved him first. And she will love him last. Kumud is the reason Saras and his entire family even came to Ratnagiri.
She is like two steps away from being Pramad, she doesn't want to accept that people deserve the freedom to make their own choices. She may choose to allow herself the "love" of Saras, but it does not mean Saras or anyone has to respect it.
It felt like when Kumud was getting hitched Kusum wanted her clothes and essentially wanted her life. She started dressing and styling herself very much like her older sister. But this is another flaw in her thinking. That by looking like Kumud, she could somehow become another Kumud in Saras' mind.