All you need is any ubuntu vps - in fact any systemd distro if you ignore the "ufw" commands - and the 50 or so lines following "Wireguard Setup".
It doesn't get more simple than this.
Just copy/paste them commands in any linux vps. You don't need aws, at least lightsail is cheap. Ionos (1&1) is cheaper.
You could totally use an Ansible playbook. I've used a lot of them over the years. Ansible, Terraform, Salt, Chef, Puppet, etc... As I said at the end of the article I glossed over a lot of things and the beauty of tech is there are lots of ways to do things. Do what works for you. Tradeoffs all over the place.
I do think that shell scripts provide lower level insight to people that may be trying to understand what is going on rather than the magic of something like Ansible that abstracts things away. Or maybe I'm just old school :D
But also one more dependancy.
More and more I'm finding having a bash script that can work on most debian/ubuntu systems is pretty handy to be able to run remotely whether it's a VPS or more.