> I love that I know that my client will do nothing I do not tell it to do.
By this line of reasoning, you would have to manually approve every init process that your computer would want to start every time you boot it up.
"images" == "client doing things I don't tell it to do" is completely false. Clients have been built that have configurable policies for loading images and scripts, and they're conceptually very simple and easy to use - e.g. "don't load images by default, click to load temporarily, control-click to load and permanently whitelist" is an example of a user-agent policy that not only supports images, but conforms to your extremely convoluted definition of a user-agent "do[ing] nothing I do not tell it to do."
> requires more requests
Is the purpose of a document browser to minimize requests, or to actually serve useful information? Images can encode data that cannot be encoded in text, and a vast quantity of information is much more easily read and understood in graphical form. If you want to minimize requests, then just don't use the web at all.
Also, this isn't even necessarily the case. You could encode images as part of the page, as base64 or something.
> they are an accessibility nightmare (as we have seen on the web)
The web supports alt-text for images. When people don't provide alt-text, that's not a technical problem, that's a social one.