Author here. I am actually participating pretty causally at advent of code and don't try to get into the global leaderboards (I wouldn't be able to, even if I would try).
I build the tool for myself last year because I like the comfort of not having to switch between terminal and browser. As I wanted to use it this year again so I decided to put it into a separate repo and to share it here.
But I see the point that this a special kind of laziness not everyone can relate to :)
i watch someone who consistently places top 5 on youtube. they code in vim on windows in the terminal, exit vim to run at the command line, and then copy and paste from the terminal into a browser.