I think the benefit of WSA is that Microsoft is significantly more trustworthy (shoot me, fml) than whoever is making the popular Android emulator of the day.

edit: Just noticed Anbox and Waydroid are open source projects for Linux. Can't say much about them. I was thinking in terms of other Android emulators on Windows like BlueStacks.

Anbox is old stuff. Waydroid is improving with each release (which happened several times in the last few months), and it's great overall, but tricky to set up properly: kernel modules, mutter (if your desktop is under X), and the Google activation step for your new device; then houdini and possibly other stuff (eg. to fake wifi if using ethernet, Magisk...). Once you do that, it's almost as native and it usually supports your GPU.

I tried to use Anbox a few times over the last 4 years, it doesn't work.

I'm sure I could get it to work on a dedicated system, where I matched whatever point release of the kernel and userspace it was designed to run with, but on a normal debian (I think it was buster) install it "shat the bed" so to speak and didn't even offer the reward of actually running the apps I wanted to.

My experience with Anbox and Waydroid on recent Linux kernels wasn't great. The kernel modules required were a major problem that made my laptop unbootable several times and just didn't want to load on my desktop.

WSA is a VM

Anbox/Waydroid are containers, they are native