The good news is, based on the diagram looking like it's straight from AWS docs, there's a Cloud formation template for all that.
Bad news, good luck troubleshooting any of it if something breaks
Arstechnica runs on WordPress on AWS, and they have a really nice series of articles about it.
Sure, you could use just one EC2 instance for everything, but on a high traffic website you would need a bit more.
And then you find out you have that dependency but your linker decides to not take it and then you have it but a slightly other version and you decide it's not worth it
Installing WordPress through a traditional Apache server shared hosting account only requires one click, and you can host as many sites as you want for like $9 per month.
Been out of the game a long time. Is Wordpress still used heavily or are people shifting to other platforms? For all the easy power it had, it always required convincing to do what it wasn't originally intended to do. Dunno if that's still the case but seems it.
I had the same impression until recently. It's now evolved into a high end, professional content management system and a ton of very high traffic sites use it. Wired runs on WordPress. Here are some other sites
Last time I tried aws, took me like four hours to figure that I had to borrow another IP address (different than the ip I received when created the instance) in order point it at my domain. Took me a long time find that option in the menu too
Autoscaling isn't only used the grow the number of servers under load, but also to guarantee availability of a fixed number. If the max is set to 1, the bastion host is protected against hardware failure, zone outages, or just you screwing up.
Accidentally killed your bastion host? No problem, within a few minutes autoscaling will have provisioned a new one and you're good to go again.
From my personal experience, AWS is extremely powerful (especially on security and networking). If you cross the learning curve, and know automation or Infrastructure as Code (e.g. Terraform) then it's fast and easy to build almost any architecture.
But yes, it's overkill for a simple website or a simple setup (if one is not familiar with AWS).