> Could there be a less powerful subset of C You probably meant minimal superset of C (as C doesn't have nontrivial or similarly performant memory-safe subset)

> Could there be a less powerful subset of C You probably meant minimal superset of C (as C doesn't have nontrivial or similarly performant memory-safe subset). And probably, although its niche would be smaller. Either you have complexity in language or in code. Systems software is more often larger and more complex so it less often makes sense to choose language that's easier to learn that is then harder to write in.