I'm not referring to copying the actual style but rather copying the habit of wearing the same thing as a way to avoid spending time making the decision of what to wear. This concept was written about ad nauseam about a decade ago, with Jobs as the inspiration.

I don't assume Jobs was the first one to do it, and it's certainly more conspicuous that Holmes was copying Jobs' style, but I do assume that people like Zuckerberg copied Jobs directly as a result of hearing that this was some little productivity hack for Jobs. I associate this period as the same time the 'personal brand' was becoming more popular, and people started aping Steve Jobs as a way to either deceive people just through perception or as a good faith attempt to be like Steve.

https://medium.com/swlh/why-successful-people-wear-the-same-...

https://www.businessinsider.com/highly-successful-people-lik...

https://www.ctsolutionsglobal.com/post/2019/09/12/what-do-st...

https://www.businessinsider.com/steve-jobs-productivity-hack...

Here's an article that includes a quote of Zuckerberg explaining himself, which makes my speculation less of an assumption:

https://careers.workopolis.com/advice/the-reason-mark-zucker...

> “I really want to clear my life to make it so that I have to make as few decisions as possible about anything except how to best serve this community. There’s actually a bunch of psychology theory that even making small decisions, around what you wear or what you eat for breakfast or things like that, they kind of make you tired and consume your energy. My view is I’m in this really lucky position where I get to wake up every day and help serve more than 1 billion people, and I feel like I’m not doing my job if I spend any of my energy on things that are silly or frivolous about my life, so that way I can dedicate all of my energy towards just building the best products and services and helping us reach our goal and achieve this mission of helping to connect everyone in the world and giving them the ability to stay connected with the people that they love and care about. So, that’s what I care about. Even though it sounds silly that that’s my reason for wearing a grey t-shirt every day, it is true.”

> He then pointed out that others throughout history have done the same, like Steve Jobs, who was usually wearing a black mock neck.