I'm now in a position where I'm interviewing and helping shape my organization's hiring practices. We've debated all the different approaches, some people like projects, some like algorithms, and some don't want to do either to get the job. At the end of the day, I really just want data on a candidate's ability so that I can say Yes.
There probably lies the disconnect. For me, interview projects should assess how well I could perform in the position I'm applying to. And thus, if nothing else, interview projects should be relevant and practical.
It seems to me that Triplebyte's project choices were made based on how interesting developers might find them, and sheer technical challenge. Some might appreciate this, but personally, I'd rather learn new skills and challenge myself on my own terms.