VirtualBox isn't any less native than UTM on macOS, both are third party apps using native GUI frameworks which use hypervisor.framework provided by the OS to do the virtualization. Similarly on Windows it's using the Hyper-V backend these days so it can coexist with virtualization based security and WSL2 which also require Hyper-V manage the virtualization on the host. In that case though Hyper-V on Windows does actually have a 1st party and native user app too but it can kind of be a pain if you want to do more than a basic install (though you can do a lot more if you drop into Powershell). Hyper-V has also been deprecating and removing the easy GPU paravirtualization whereas VirtualBox still has GPU acceleration options for all types of guests (UTM/QEMU really only have usable acceleration on Linux guests).

I don't actually use VirtualBox much these days, e.g. on my Mac I use Parallels for the better Windows integration and GPU acceleration + the Oracleness of VirtualBox you mention, but there still aren't necessarily great "native" options that universally beat out plugging something extra in instead. I'm not sure what's best on Windows these days but it probably also depends on how/what you're wanting to virtualize (headless Linux servers on a fixed box vs various GUI operating systems on a laptop are probably going to get different sets of recommendations from people).

As someone who hasn't used VMs (on my machine) in a very long time, but went through the conversion of VB to Virt-Manager, the UX of VB was a lot better. It was easier to understand. I powered through and got used to it after a lot of issues.

I don't like the Oracle influence either, but the free version still works well enough for my personal use - playing old Windows games a few times a year and occassionally trying out different Linux distros or BSDs - that I haven't had reason to change. I like the UI and it's easier to use than the alternatives.

I haven’t really seen Oracle “getting all Oracle” with it. They changed the release schedule to match their other patch schedules (quarterly instead of monthly), and the only other thing is the extension pack needs a license, but that was never open source. Almost nobody actually needs the functionality the extension pack provides, so it has no impact on regular usage.

The extension pack is different from the guest additions, which does not need a license.

Last I tried, I think VirtualBox might have been the easiest route to run MacOS on Windows (AKA "Hackintosh").

Only reason I'd use it over QEMU/KVM is that it has 3D acceleration for Windows guests.

It was easy to install with apt. And I use it once every three months for windows. Why change?