I get the point in the article, and I do think a lack of feedback does contribute to this in some way (especially in smaller or newer companies where getting an

I get the point in the article, and I do think a lack of feedback does contribute to this in some way (especially in smaller or newer companies where getting any sort of code 'review' is pretty much non existent), but I think the simplest reason for imposter syndrome might just be same as the reason so many are unhappy on social media. You just can't see how much other developers might be struggling with issues. You can picture your own struggles and time online looking through Stackoverflow answers and documentation and what not, but not the nightmare some other 'better' developer might be having with their own work. So you think other people are simply not struggling, and hence know more than you do, or can pick things up more quickly, or whatever else. Maybe it's just more of a 'grass is greener' thing.