This is specific to page reclamations, which only occur when the kernel is removing a block of memory from a process. VMs in particular pretty much never do this; they pin a whole ton of memory and leave it entirely up to the guest OS to manage. The JVM also rarely ever returns heap memory to the kernel - only a few garbage collectors even support doing so (and support is relatively recent), and even if you have it configured correctly it’ll only release memory when the Java application is relatively idle (so the performance hit isn’t noticeable).
This is specific to page reclamations, which only occur when the kernel is removing a block of memory from a process. VMs in particular pretty much never do this; they pin a whole ton of memory and leave it entirely up to the guest OS to manage. The JVM also rarely ever returns heap memory to the kernel - only a few garbage collectors even support doing so (and support is relatively recent), and even if you have it configured correctly it’ll only release memory when the Java application is relatively idle (so the performance hit isn’t noticeable).