I think the point that OP bitL was getting at is that:

There is a large class of people who are not confident about an autism diagnosis.

They read an article like this looking for clues and discriminators about their autism status, and to better understand where they fall on the spectrum.

When the feedback is: "Don't many people have that problem?", it's not meant as a jibe or an attack on the struggle of autistic people. It's meant to ask: "So how do you tell if this symptom is predictive of autism, and why?"

So the answer to the first question, fellow readers, is "Yes, but not to the degree that they read an article about it and wonder if that's them"

It's like one of the pages with autism spectrum testing tools says: "If you take all of the tests on this page, you're probably on the autism spectrum." - most people won't diligently spend 3 or 4 hours trying to see if they're autistic, to a degree that is somewhat diagnostic.

The best tests available are things like https://psychology-tools.com/test/autism-spectrum-quotient - for reference, I'm diagnosed, and before I took it, I got a mid-level score, because I didn't understand the comparative degree to which those things were true for me, e.g. "I often notice small sounds when others do not" - how do you know if you aren't aware and ask?

So, it's a bit like the old saw about "If you have to ask, you'll never know" - it's worth seeing a mental health professional and asking them, because they can provide you the feedback that people on the spectrum are critically missing out on.

That’s right. This way of expressing similar experiences is actually sympathy, not empathy. And sympathy tends to be unhelpful for the person sympathized with, if not actively counter-productive.

Imagine complaining about an argument with a friend and your friend sympathizes by saying “yeah, I hate him too, he’s such an asshole”. Now you have to empathize with them, while also being unhappy about how they feel about your friend.

Yeah, I guess it's way more difficult for autistic persons :-( Aren't there any supplements that could "boost" the brain to at least decrease the burnout rate?

It may not be as simple as "supplements," but there are probably dietary and habitual augmentations to bolster these neuro-physiological resources. Sleep is crucial for replenishing neurotransmitters. Exercise is crucial for establishing biorhythms necessary to sleep. We're all fairly malnourished, given the modern western diet is biased towards cheap calories. Copper. Zinc. Iron. Deficiencies in all of these can cause mental health issues. Then there's the notorious (tenuous?) connection between suicidality and gluten.

Anyway, you can do your own research but as for supplements to facilitate extroversion... B vitamins?