This is such a great way to find out just how much can be done for you.
I used to do competitive programming competitions (similar to HackerRank challenges) and learning the standard library was a huge driver to finding the best solution without reinventing the wheel.
But even in the day job, knowing what to use without pulling in a new dependency can make a big difference.
This can go a little further to learning common packages that your ecosystem uses, and how best to tackle problems with them.
Recommended read: Learn your standard library https://letterstoanewdeveloper.com/2019/03/11/learn-your-standard-library/
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