So the problem with the article is it's a guy who skimmed a bunch of studies and then vomited up a bunch of blogspam for SEO.
The discussion of Niel Patel is a giveaway - I've followed Niel Patel for a while. He's one of the acknowledged masters of white-hat SEO. And by "white" we mean "just this side of getting Google to pop a cap in your ass" because most of what he does would be considered disingenuous or opportunistic by people who don't know much about SEO. It doesn't surprise me in the slightest that Niel Patel made more money as soon as he started dressing like a consultant; if you have your choice between paying his rates (which start at like $20k and work their way up) for a guy who looks like he does SEO or paying his rates for a a guy who looks like he speaks at corporate events about SEO, go for the stuffed suit.
And that's really what every single example listed is: signaling within the constraints of a predefined professional relationship. To whit:
In the high-status condition, participants donned a business suit, buttoned shirt, slacks and dress shoes purchased from Macy’s. In the low-status condition, participants wore sweat pants, plastic sandals and a white T-shirt purchased from Walgreens. As justification for the clothing change, we explained to participants that the apparel had state-of-the-art physiology monitors, and that the study was a venue for testing this equipment. Once dressed, these participants entered a second room, where they met their partner (the neutral perceiver) for the first time. The two participants then engaged in a competitive negotiation in which they acted as chief financial officers of rival biotech companies tasked with coming to a consensus on the sale price of a valuable asset. Participants could improve their personal monetary gains in the experiment by negotiating for a more favorable price for their company. We then compared the negotiations between high status vs. neutral, low status vs. neutral, and neutral vs. neutral pairings.
That's not a study, that's play-acting. It's not surprising that play actors do better when they're wearing the right costume. Uniforms didn't come about because people enjoy playing dress-up, they came about because uniforms pre-load social expectations. Car mechanics wear blue coveralls. Dentists wear white lab coats. What outfit do you think watchmakers are expected to wear?
The problem is, the author doesn't fully understand the basis of the signaling or how to use it to your advantage.
Go custom with Indochino. Suit prices have significant differences based on brand name. Even all the research behind wearing a suit, going bespoke could help even more. Research of 274 participants measured confidence, success, trustworthiness, salary, and flexibility for men wearing an off the rack vs bespoke suit.
The research, which is spurious at best, says that a well-fitted suit looks better than an ill-fitted suit. It doesn't say "buy Indochino" because they're basically Zara for scrabblers. Picking up a used anything that's a little to big and hauling it to a tailor is going to look better because the material is going to be substantially finer, the fit will be substantially better and you can pick up used suit jackets and pants for a song.
Watches. Look to Filippo Loreti. This watch company makes $1,000 watches directly to the consumer for less than $500. Starting on Kickstarter, the company raised $926,620–the most crowdfunded watch company ever.
And everyone who knows anything about watches will tell you that showing up in Kickstarter watch is like wearing a "designer impostor" fragrance from the drug store. The people who don't know will only notice something offensive and the people who do will be actively repelled by your poor taste.