No.
Let’s review:
Ropers was replaced by Don Knotts, who was usually excellent but seemed uncomfortable with comedy and whose role consisted mostly of playing the camera and flirting with the female cast.
Suzanne Sommers was instrumental in the show’s success. After she left, the series slowed down with two replacements, neither of whom garnered much fan attention.
The show tried to “promote” supporting characters like Larry (the upstairs neighbor) and introduced Lana as a sexual object for John Ritter’s Jack Tripper. Neither move worked, and the show began to decline.
When John Ritter was given the sole lead role (and introduced his future wife on the show, another unsuccessful actor), he was not up to the task. His antics and rudeness became tiresome because they were clearly forced; and character development was never prioritized.
The writing did not improve. The show’s best performances were during the Roper/Sommers era, and after that, the series simply became an exercise in mediocre television storytelling.
Ropers should have stayed and Sommers should have been kept. Losing both was the beginning of the end for the show as a viable entity.
