Although this feature does improve security, it is due to the CPU, the VM and the main idea was to reduce performance overheads. I do not see adding layers and

Although this feature does improve security, it is due to the CPU, the VM and the main idea was to reduce performance overheads. I do not see adding layers and layers of abstractions the same as more secure. In fact, meltdown and spectre serve as counter-examples. Also, one can achieve similar effects with containers as well, just think AppArmor, capabilities, permissions, etc., all layers of administrative privileges between some untrusted code and the host.