I suspect most folks, especially ones which operate at GB/s rates serving traffic would not like to serve up a 100kb base64 encoded image every time an error is thrown.
Sure, which is why they probably wouldn’t serve up a 100kb base64 encoded image every time an error is thrown.
It’s more than possible to embed a small vector image to add some humanity to an error page without breaking the bank, bandwidth-wise
Browsers send the Accept headers, and I have configured my CDN to return a plain text page for static assets (that users wouldn't see on the browser), but text/html requests get a useful 10-20 kb response. Should be a trivial thing to setup.
Or just cache the image with a major CDN, like Fastly. No wait...
Why not? The non-error page was likely much larger.
We create separate 404 and 500 error pages. Question is - should we do this for most status codes?