I read a paper 'What If We Don’t Pop the Stack? The Return of 2nd-Class Values' where they discuss their research into delaying popping the stack to allow functions to return data allocated on the stack. As a small brained embedded primate that doesn't use malloc that sort of thing would make C vastly easier to use.

https://www.cs.purdue.edu/homes/rompf/papers/xhebraj-ecoop22...

Also would be super if C had first class types.