I had a take-home assignment to build a Dropbox competitor around 10 years ago, it was a pretty big project but I actually still use it for sharing files with friends because it's legitimately much easier to use than Dropbox.
> I had a take-home assignment to build a Dropbox competitor around 10 years ago, it was a pretty big project
I'm genuinely amused you thought (think?) it acceptable to do such work without payment. Here, any potential employer submitting such a request would be laughed at.
Well, technically if he isn't getting paid, it's his copyright, allowing him to use the code and even create a business around it, and the company has no rights to it- so in this case it worked out well for him.
But yes, its a pretty crappy idea that people should do 'real' work for free to get hired.