That depends on the project. There definitely are projects in which micro-optimizations such as this wouldn't be beneficial for one reason or another, but there definitely also are ones where they're make-or-break. For those, C is pretty good, and you're not fighting against the language (or the core intent of the language at least).
(I'd guesstimate that micro-optimizations would go a very long way in improving performance of nearly every program anywhere, but I don't have much data on that besides the couple projects where I've tried to care about performance, and having achieved pretty decent results)
But I seriously doubt that programs would benefit much from these micro-optimizations - there are rare and unfortunate cases where indeed there is no one single bottleneck for a program and thus there is no simple way to improve performance, but the vast majority of programs spend all their life in a tight hot loop, and anything else doesn’t matter in the slightest - hell, as mentioned C gets away with as many linked data structure as they want, but writing those in goddamn bash would suffice as well.