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
In theory yes, and I've had a few zealous support engineers there do their absolute damn best to fix cloudformation infra issues. But there's only so much they can do because the template was probably written by a 3rd party vendor (if it was how you can set up said vendor solution using AWS native features) or a consultant who fucked off to other projects.
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.
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).