My own theory is that Trump's supremely narcissistic cult of personality was necessary to actually convince millions the election was stolen and have them do something like storm the Capitol for him. Guys like Mastriano are ultimately so weak, so in need of being told what to do by an authoritarian figure, that they'd rather fight for Trump than for themselves!
Now, if Trump himself decided to go to Phoenix and hold a rally for Lake, it might result in a different outcome. However, he's too narcissistic to do such a thing for anyone but himself, even someone like Lake who completely debased and humiliated herself for him.
