As a developer you constantly want to learn and improve your coding skills. And solving coding challenges on Coding Challenges Platforms is one of the things that will help you improve your coding skills and prepare for technical interviews/assessments.
I mean besides working on personal projects :).
How they work.
Some of the advantages with solving these coding challenges is you get used to these kind of challenges and since most recruiters or potential employers use the same platforms to test your skills you will be used to solving those kind of challenges, and know your way around these coding platforms.
There is more but these are my faves :).
Note: At first they might seem a little difficult but you got this and you'll get used to them :).
Happy Coding :)