I like re-implementing things too! But usually there's a pretty clear difference between "I'm doing this deliberately differently from established-solution X for reasons Y and Z" vs "I'm doing an unrelated task and am using urllib because I'm blindly copying in SO solutions from ten years ago and have never heard of Requests." This kind of thing is the fizzbuzz of ecosystem-awareness.

For an example from my own code— I was learning Rust via AoC a few years ago, and I deliberately chose to do some of the challenges with natural language inputs using Pest rather than just dumb regexes [1]. The regex solution would have almost certainly been shorter and quicker for this limited task, but I would have no trouble justifying this design choice to an interviewer as having been an intentional learning experience.

[1]: https://github.com/mikepurvis/advent-of-code/blob/master/202...