I have a friend group that insist on all events being planned through facebook.
I’ve missed out on events in the past due to not taking part.
It’s no longer a hill I wish to die on.

I agree and use Signal myself.
But people like the extra features of WhatsApp like desktop/web clients with seamless history sync and all the other little things that WhatsApp provides.
The average Joe doesn’t even think about security or privacy, they just know that the results of using WhatsApp are superior than using SMS.
iMessage is a non starter everywhere out of the US, it just doesn’t have the market penetration.
As an Australian, no one I know (many of whom own iPhones) talk about the blue-green bubble stuff.
They recognise where the fault lies and simply don’t use the app.

In certain places like India, WhatsApp is the default means of communication for everyone.
You can use it without phone data if you are on wifi, it supports better quality than sms for sending images, you can video chat with it, it’s cross platform, etc etc.

What’s more amazing to me is that it’s not more popular in western countries.

I think all the existing answers are on the basis of creating a new Linux VM.

And if I understand you correctly, you already have a bare metal Linux install that you want to run whilst Linux is up.

This is the best search result I could find: https://forums.virtualbox.org/viewtopic.php?t=93437

It sounds like Virtualbox will indeed create a pseudo vhdx that points to a real partition, but windows is going to give you permissions drama.

The above link is out of date though, so its best viewed as info rather than guide.

Good luck.

A lockdown browser?

If you need to use windows because of a software issue, not a hardware issue, you’re probably best off running windows in a VM.
That way your linux install is making the WPA3 connection, and as far as the Windows install is concerned, it’s on a wired lan.
This has the added benefit of not having to reboot, you just always start linux and turn the windows VM on and off as required.