I mean a readable implementation of tuple with minimal overhead is a great case for me (went from around 1.6k lines to approximately 250 lines). I wrote an implementation including the normally difficult to implement tuple_cat based on c++26 within a few hours.

My favorite thing is that I will get to remove and replace most of the cryptic template recursion stuff I have with "template for" and maybe a bit of reflection. Debugging the unrolled stuff will be a joy in comparison.