

XBPS-SRC does not look like an alternative to AUR at all. It looks like Voids alternative to https://gitlab.archlinux.org/archlinux/packaging/packages - where Arch maintains all its packages. Nor is comparing the number of packages in AUR to Void main repos a good idea - Arch has its own main repos that are a better equivalent. The Void templates do not look dissimilar form what a PKGBUILD file is either and you can do the same things with writing your own PKGBUILD or pulling them from repos if you really want to. I don’t see how void is any better then Arch in anything you have described here. IMO it just looks like it does more of the same things with a bit difference in syntax/commands you run. Nothing you have said here is really a solid argument for using Void or Arch at all.
The AUR is not even that great. I think most people seem to get confused between what is in the AUR and the main packages since they just use tools like yay that install from both. But most people only use a couple of packages from the AUR - it is the package selection in the main repos which is what is so nice about Arch. The AUR is just nice for more niche things that have not made it into the main repos yet.
I hope u don’t use AUR blindly and just do yay -S something without looking what pkgbuild is doing, it might be dangerous not knowing what program can do and what script that is downloading it too right?
Same goes for Void? Most people wont read the source of third party packages they install. No matter what distro they are on. AUR tooling does try to help with this but most people ignore it. Same will go for Void. It is not a distro problem - just a humans are lazy problem. Plus even if people did read them there is only a small subset of people that actually understand them enough to spot obviously malicious packages - though that can spot hidden malicious packages are vastly smaller.
From what I can tell xbps-src are just the source packages to the main repos in Void. That is not what AUR is. We have access to the main repo sources in Arch just like Void. The main thing about AUR is anyone can contribute without any gated approvals. That is the big difference between the main source repos of either distro and AUR. Unless I have misunderstood what xbps is.
Same exact idea with PKGBUILDs. No benefit to Void here. The way Void does things will not change people looking at or understanding the packages they install. You have the same optitunities on both systems for looking at the source of packages. So that argument for Void is void :)
Not really a good argument either. Systemd and runit are different but that doesn’t make runit better in terms of learning anything. If you want to learn how most Linux systems boot and operate you need to learn systemd as that is what the vast majority of distros use. Learning runit instead only means you are learning a niche way of booting a tiny fraction of systems.
Neither of these arguments are a very strong case for Void over arch.