> On the other hand, it must be noted that there's a ton of subtle timing-related attacks in crypto where low-level control of memory layout strongly benefits their mitigation [1]. I don't know how mechanisms provided by languages like Rust fare into this, though C has definitely been tried and tested well.

Rust has the same control over memory layout.

And Cyclone used a GC; it wasn't as minimal as you think. The stuff needed to actually get rid of a GC while maintaining memory safety (retaining dynamic memory allocation) didn't really get developed in a practical way (IMHO, anyway) until Rust came along.