Perhaps ‘fear-mongering’ was a little strong in this instance, it’s more a case of ‘catastrophe-fetishism’.
I’m not trying to downplay the severity of the situation at hand and I’m not disagreeing with Umair’s assessment, he is a brilliant writer and I wouldn’t try and argue against any of his well-thought out & researched pieces - but I do think it’s clear where the priorities of his writing-style lie; building an audience around his ego, using divisive language without much consideration towards a real solution or level-headed discussion. I would never compare what he does to the groups you reference but I’d say their priorities aren’t dissimilar and therein lies my issue.
I see Umair as trying to fight fire with fire — that’s not an effective way to solve the many problems facing the US in my mind. That doesn’t mean be weak or naive when faced with the collapse of American democracy, rather, I just think its better to keep a cool-head when tackling the challenge as opposed to doomsaying.