Depends on what you mean by "operating systems". NT, Darwin, and Linux kernels have not been replaced, true. But an operating system is not just the kernel. There have been many different changes underneath the hood that are not as evident to non-technical users as UI revamps. I won't speak for Windows, but Linux saw many innovations both in kernel-space and in user-space, for sure. For example, systemd, Wayland, and PipeWire.
Then there's Fuchsia, which is not only a different OS, but a completely new kernel.
Depends on what you mean by "operating systems". NT, Darwin, and Linux kernels have not been replaced, true. But an operating system is not just the kernel. There have been many different changes underneath the hood that are not as evident to non-technical users as UI revamps. I won't speak for Windows, but Linux saw many innovations both in kernel-space and in user-space, for sure. For example, systemd, Wayland, and PipeWire.
Then there's Fuchsia, which is not only a different OS, but a completely new kernel.
Oh yeah I completely forgot about all of those lmao. Fuchsia particularly.