First I am glad they finally updated the arch wiki; it was bad out of date.
The RPi folks has backported the android modules to the 5.4 kernel so do not install the dkms modules and do not modprobe them as they are built in the kernel.
What ever you have done along the way should be probably reversed and uninstall the anbox packages and start fresh; especially the anbox-modules-dkms-git package if installed. Then:
sudo pacman -S anbox-image-aarch64 anbox
Then reboot as there are some udev rules that needs to be picked up. Then:
sudo systemctl start anbox-container-manager.service
Then click on the Anbox icon in the menu to start it.
It will say Starting… for a while while the image is being decompressed although I do have it set to use all cores in the kernel. Here is where a usb drive would come in handy for speed.
After you get it going you can enable anbox-container-manager.service if you want it started at boot if desired. Also be advised that anbox has a way to go and is a little unstable and will crash trying to load some programs.