In order to keep the binary layout of a program simple and convenient, most languages store information in 8 bit (1 byte) blocks.
If you allocate a `bool` in Rust or (most) other languages that are based on LLVM, [it will take up 1 `i1`, or 1 byte of memory](https://llvm.org/docs/LangRef.html#simple-constants). If you allocate a boolean value in C, you will get [an integer constant with a value of either 1 or 0](https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/stdbool.h.html).
This example still wastes 5 bits since we only use 3 out of 8 possible bits of the char type, but I'm sure you get the point. Allocating 3 boolean values independently would waste 7 * 3 = 21 bits, so it's a massive improvement. Whenever you find yourself needing multiple boolean values, think twice if you can use this pattern.
Microcontrollers have a very constrainted environment, therefore bitwise operations are essential in those scenarios. 7 wasted bits are a lot if there are only 4 kb of total memory available. For larger systems we often forget about these constraints, until they add up.