Everyone should have a healthy way of dealing with feeling inadequate, besides whining. (e.g. learning things)
The solution for dealing with actual imposters is to fire them. If, somehow, they manage to use "imposter syndrome" as a deflection (I haven't seen this play in the wild and I'm not convinced it's prevalent or even could be made to work), then gather evidence that they aren't pulling their weight and proceed to use it. If that doesn't work, it's not because of some stupid blog post, it's because there's stronger politics at play. Abort/retry/ignore as warranted.
That's a good idea in general, but it doesn't address the specific problem of imposter syndrome.
> This is something imposters don't do.
If you believe that this is true then it addresses the problem of imposter syndrome. The danger is that you might then have to deal with cognitive dissonance if you were confronted with someone who ramped so slowly or started from so far behind that they couldn't be expected to make a net positive contribution to the team within a reasonable timeframe. It's entirely possible to try and fail, and while we should all admire the "try," that doesn't mean you or your employer should be on the hook for funding it.
This is how I've coped with possibly-impostor-syndrome-or-actually-impostor-idk-lol anyway. YMMV.
And, of course, don't ever let imposter feelings getting in the way of diving headlong and trying things anyway, even if they seem impossibly difficult from the outset. It's mostly mental barriers; I've tackled dozens of tasks that were imposingly difficult from the outset. There hasn't been a single one yet that I didn't end up making appreciable headway on.
What I am actually worried about are arrogant developers. They tend to cause the most damage, write the most "clever" code, have the worst communications skills, and will be the first to leave the team in the lurch and panic when shit hits the fan.
There may of course be arrogant developers who can walk the talk, but I'm taking from personal experience.
The ones with "Imposter Syndrome" - i.e. those who have a fear they're not quite good enough for the job - are more likely, again based on personal experience, to double check everything, to ask questions (from the rest of the team or Google), to write tests and test manually. They write "dumb" code that works and is well-commented and is as simple as possible. They have a desire to learn.
So, how do we find out which people are whining and which aren't? How do we encourage people to just learn and self-improve rather than sink to escapism?