Three's Company tried that when Suzanne Sommers left and Priscilla Barnes took over but the ratings suffered a slow decline and the show got cancelled after three seasons.
I think what helped was that the show became more of an ensemble whereas before Cheers was the Jack and Diane show. The first two seasons with Kirstie was clearly them trying to have Sam and Rebecca be the focus with Sam constantly trying to woo her but then they quit that and it became a ensemble with everybody getting to shine.
For me, I thought Alley was funnier than Shelley Long but Long was a better actress.
This was all before people started to get called out for “fat shaming” and fat jokes were fairly common. However, something always seemed a little more personal for him with Kirstie Alley jokes. I have created several scenarios in my head and I have decided to believe that she was extremely rude to him or SNL staff when she hosted in 1991 - before Late Night.
I feel Long was too shrill and whiny and the whole "I'm too snooty to work in a bar" got old pretty quickly. I was tired of how much Long was a fish out of water and I didn't think she and Ted Danson had this great chemistry.
I thought Alley was funnier, she made her character into a total loser but unaware of it and I liked that she was at times unlikable. It was more entertaining to see Rebecca fail at everything than Diane complaining about how she's too good to work in a bar and her love-hate relationship with Danson.
