Yes, but.

The problem with OS file caches has ever been that people look at a box, see that the programs aren't consuming all of the available memory, and argue that they should be able to cram more shit on the box because it's 'underutilized'.

There are very reasonable and sane system architectures that let the OS handle caching, but you need a way to defend against these sorts of situations.

The performance falloff for this failure mode is exponential, so people try it a few times, and not getting any negative feedback, they add it to their toolbox only to get lectured months later once the bad behavior has not only become standard for them but also spread to other people.

It almost begs for a different system call that can earmark the memory usage by the app in a way that's easier for people to see.