Who are you?

This may be true but without evidence is sounds like exactly what the OP is complaining about.

His LinkedIn doesn't even claim any business building before 2.5 years ago. https://www.linkedin.com/in/damengchen It only claims he built 2 things.

It ought to behoove us to ask this question for every blog post of this nature thats posted.

Does it matter?

Of course it matters when you attempt to use your own social backing to boost someone else. That you're a commenter who has been around since 2018 who is also an "an ambitious full-stack software engineer, with a deep passion for design, user interface and front-end engineering"[1] is definitely a point in your favor, though. What made you personally feel so strongly about the original author? Your reasoning is more likely to help convince others especially if you have sources you can point to.

[1] I'm hoping he'll notice but for everyone else, I pulled this quote from the About page on the website linked from his profile.

Who are you to make those kinds of statements?

lol