This has been the standard way of serving assets in Rails for the last 5+ years. I don't think it was invented there, as if you are using a CDN it's basically required.
Invalidating edge caches takes time and/or is expensive (i.e. Cloudfront), so adding the content hash in the file name is a good trick to ensure users always get the correct version of the asset.
I didn't mean to imply it was invented by webpack or anything (and I used the scarequotes around modern because I'm not sure how long it's been widely used).
I was just pointing out how and with what I use it.
Invalidating edge caches takes time and/or is expensive (i.e. Cloudfront), so adding the content hash in the file name is a good trick to ensure users always get the correct version of the asset.