Earlier quoted context omitted.
"Look at what other apps are doing and copy it!" Agree that most of the time this is horrible direction, but I've also experienced the opposite: "We need something like X, but do Y." Where Y is reinventing the wheel for what should be a standard interface element (ie it's the best implementation on the market and ours would only be worse/confusing if we didn't try to do the same).
Utilizing existing patterns can be good for sure, especially if they're platform standards from the likes of Material or Apple's HIG. But what makes leveraging those existing designs so effective isn't simply seeing and copying them (that'll do in a pinch, but ultimately may lead to misuse). What makes standard patterns from platform sources so effective is that you don't have to wonder whether they'll meet your need…
That said, if you are a scrappy startup (or in the case of an article, a single founder who may not even be a designer to begin with), it is often necessary to simply do whatever it takes to deliver a product. Money, time, experience, infrastructure, personnel, etc., are all limiting factors.
If I were consulting on a project for a Fortune 500 I would tell them to leverage their resources to maximize their change of success. If I were consulting on a project for a small business or startup I would tell them to be smart and triage key pieces that represent their "special sauce" above features that feel more like known territory.