Yes. As far as kernels go, NT was pretty damn good.
So is Mach, by the way, if you can afford the microkernel performance overhead.
XNU monolith-ized itself over time, even over some microkernel-esque boundaries.
If you include all the drivers too (which surely makes the comparison more accurate), is that still the case?
Mach is not a very good microkernel at all, because the overhead is much higher than necessary. The L4 family’s IPC design is substantially more efficient, and that’s why they’re used in actual systems. Fuchsia/Zircon have improved on the model further.
Someone will of course bring up XNU, but the microkernel aspect of it died when they smashed the FreeBSD kernel into the codebase. DriverKit has brought some userspace drivers back, but they use shared memory for all the heavy lifting.