While Roseanne Barr may have been the original star and creator of Roseanne, The Conners not only improved by killing Barr's character but saved itself from potential cancelation. It's never easy for a show to recover after ousting its central character, especially given the fact that sitcom viewers generally don’t want to be reminded of reality's heavier moments. However, The Conners, like the original groundbreaking Roseanne, doesn't shy away from life's darker aspects. Not only did the decision fit in with the sorts of themes the series explores, but it benefited The Conners' popularity too.

https://screenrant.com/dropping-roseanne-barr-saved-conners-reasons/