Filmic mimics the nonlinear dynamic range response on film medium to push the contrast and dramatic look present on the shot.

It also highlights how old film struggles when compared to much more capable CMOS we have today.

I use filmic rather frequently to get the look / emotion response for a shot, however it's not always suitable. Sometimes the lighting is not favorable for it, sometimes the shot I have at hand is not well suited for that because of other reasons.

Shadow, highlights, exposure, etc. are corrective tools while Filmic tends to be an artistic one.

My other favorite tool is contrast equalizer.