How does war caster work exactly?

[JackPhoenix]

If it were just a simple manipulation it would just be a VM spell, like Suggestion, instead of VSM. The S implies some amount of gesturing in addition to just accessing the component.

So you have to wave the component around instead of just holding it... that doesn't change much.

M-only spell is holding your phone in your hand, SM spell is writting a text on a phone with single hand, and S-only spell is trying to communicate with someone using sign language... impossible to do while holding a phone at the same time.