Yes. I think mmap() is misunderstood as being an advanced tool for systems hackers, but it's actually the opposite: it's a tool to make application code simpler by leaving the systems stuff to the kernel.
With mmap, you get to avoid thinking about how much data to buffer at once, caching data to speed up repeated access, or shedding that cache when memory pressure is high. The kernel does all that. It may not do it in the absolute ideal way for your program but the benefit is you don't have to think about these logistics.
But if you're already writing intense systems code then you can probably do a better job than the kernel by optimizing for your use case.
With mmap, you get to avoid thinking about how much data to buffer at once, caching data to speed up repeated access, or shedding that cache when memory pressure is high. The kernel does all that. It may not do it in the absolute ideal way for your program but the benefit is you don't have to think about these logistics.
But if you're already writing intense systems code then you can probably do a better job than the kernel by optimizing for your use case.