I was able to get Waydroid to work in a Debian VM, so unless there’s something weird about how VirtualBox handles things, Waydroid shouldn’t care whether it’s running in a VM or not.
What happens when you run waydroid status or waydroid show-full-ui?
I have no idea why that would happen. Probably something weird about Lemmy.
As for Waydroid, it’s kinda finicky in how to start. Use something like btop or ps aux|grep waydroid to check whether you have multiple processes that are all running waydroid session start. It should just be two processes: /usr/bin/waydroid -w container start and /usr/bin/waydroid session start. I remember I had multiple /usr/bin/waydroid -w container start that I had to kill before it worked for the first time.
The devs behind Waydroid also have their own distro set up for Waydroid. You can try that as well: https://waydro.id/#wdlinux