amp-wp VS S3-Uploads

Rather than a caching plugin have you experimented with AMP, and specifically the official AMP plugin? As long as you're not using much custom JavaScript you may notice instant improvements.

1. AMP – Official AMP Plugin for WordPress

The website uses the official amp plugin available here: https://wordpress.org/plugins/amp/

S3 is intended to be used for static files. To be honest I didn't test this approach but I found the following WordPress plugin that allows to locate uploads to s3. So I'd appreciate if whoever decides to implement this setup could drop off a comment whether it works or not.

Personally, I use this one.

We maintain S3 Uploads which solves the upload problem generally. You can also use an NFS drive for your uploads mount (eg on EFS), although that can come with other drawbacks.

The solution to this example is simple and makes usage of a plugin.

S3 with S3 Uplods

A really good plugin I came across recently for S3 is https://github.com/humanmade/S3-Uploads

Create an S3 bucket using the CDK and use this Wordpress plugin to sync Wordpress uploads to AWS S3. Hint: You install this plugin via the user script.

To answer your question: here's a totally free option from HumanMade, though it lacks some of your bells and whistles, including, I believe, local deletion.

I'm using S3 Uploads to offload my WordPress Media Library to an S3 bucket. I used the AWS CLI to bulk migrate my local Media Files to the S3 bucket. So far so good.