This sounds like what is called the soap opera effect:
https://en.wikipedia.org/wiki/Soap_opera_effect
Which is generally associated with excess denoisong rather than with excess grain.
https://en.wikipedia.org/wiki/Soap_opera_effect
Which is generally associated with excess denoisong rather than with excess grain.
This comment that I replied to is almost a textbook description of the soap opera effect.
The interpolation adds more FPS, which is traditionally a marker of film vs TV production.