Hiding every URL behind a proxy seemed like the obvious response ~5 years ago[1] when the popularity of DNS filters like the pi-hole was rapidly rising. The proxy could even increase the obfuscation by rewriting URLs and filenames so every HTTP request to the proxy was just random noise:

  https://proxy.example.com/ZGQgaWY9L2Rldi91cmFuZG9tIGJzPTEgY291bnQ9NTIgfCBiYXNlNjQgCg==

However, the "end game" of adblocking is far worse - the entire page becomes this:

  <!doctype html>
  <html lang=en>
    <head>
     <meta charset=utf-8>
     <title>null</title>
    </head>
    <body>
     <canvas>Run the WebAssembly blob to render the page</canvas>
     <script src="load_webasm_blob.js"></script>
    </body>
  </html>

The entire page becomes an giant obfuscated WebAssembly blob that renders the page into the canvas tag. The technologies of the open web like HTML become legacy baggage; a "web page" is just a stub loader for what would effectively be a statically linked executable binary that uses the canvas tag as a generic framebuffer.

In this "end game", URL based blocking is irrelevant; most page assets become part of the blob. The question "is this an ad/tracker/virus?" becomes undecidable; answering any question a page's behavior requires running potentially hostile code or solving the Halting Problem. Some people don't want an open web that respects things like user agency. They want control. They want the "web page" to be an opaque binary blob that nobody can investigate or modify. They want full control over what the user sees and is allowed to do. They want TV.

[1] https://news.ycombinator.com/item?id=10294187