No. MIDI controllers have their place, but many people work without one, or only use one for live performances. There are often also way more knobs in the various FX chains in a DAW than you would reasonably want to map to a controller, but still want to touch at least a few times while making a song.

Knobs are confusing when converted to a mouse paradigm because there can be a few strategies to control them (click+drag up/down, click+drag right/left, weird rotational things, etc), and you have to guess since each FX studio and software may implement it just a little different.