Higher frames rates are good, when you actually get more frames. But motion smoothing is a fraud. It interpolates additional frames. In order to make things look consistent, it has to apply addition filtering to the original frames. The result is you get less information overall, not more.

Even worse, it tends to ruin production values when it's a film with a DoP who knows how to exploit the characteristics of film.

It's like interlaced video. Yeah, you motion that looks like 50 or 60 fps, but the actual information is still only 25 or 30 fps, and it's degraded due to the effects of interlacing.

Motion smoothing is this century's interlacing, and in a few decades we'll have archivists running video through a motion desmoothing counterpart to QTGMC.