First, you’re 100% right that the best way to assess is to watch a candidate build something using the candidate’s favorite tools, but if your resume flops, you’re never gonna reach that stage in the hiring process. That quote is about improving your chances to get to that stage.
Nobody needs a portfolio URL AND a blog AND links to products they contributed to (which may include things they built during their day job) but they should definitely have at least one of those things.
If they’re just starting out and haven’t worked in the industry before, a portfolio of learning projects (or even just one good one) will help get their foot in the door.
If they work full time and don’t have time for a side project, they better be able to point to a day-job product and say “I built the UI for that with React and here are some of the challenges I solved” or “I built the collaboration service in Node.js and here’s how we solved client view consistency”.
The point is that resumes should focus on supplying evidence that developers know how to code more than a laundry list of skill buzzwords.
Most resumes I look at tell me very little. The ones that can communicate the most confidence in the least space (about a page) float to the top of the pile fast. The most efficient way to do that is to link to some stuff you built or wrote (if it’s good).
If you don’t have any of that on your resume, why do you have time to comment on somebody else’s blog post? There are lots of jobs, but the market is still competitive, and individual employers tend to hire slowly and very selectively. For every hundred resumes they see, they might interview only ten and hire one developer, so your resume needs to be better than 9/10 resumes to get your shot at bat, or you’re going to need to apply to dozens or even hundreds of jobs to land your next gig.
Most application forms are black holes, and only a small percent of applicants ever hear back. At the application phase the ONLY thing distinguishing you from the competition is what’s on your resume or in your cover letter, and I just gave you a bunch of tips to make your resume 10x more attractive to hiring managers.