I played my Switch far more than my PS4 last year, so last year my Switch was my primary console. This year I am playing my PS4 more, so my PS4 is my primary console.
Primary/secondary console is a subjective term that varies from person to person, games releasing at the time, and in the Switch's case, how much you can utilize portability at the time with multiplats.
What I am trying to say is, those who think Switch cannot be or is rarely a primary console are either looking at their own personal preferences and nothing else or straight up lying to themselves.