Hologram author here. It's the opposite, really - the whole thing is built on web technologies. The compiler builds an IR from your Elixir code, analyzes the call graph, and spits out per-page JavaScript bundles. In the browser it's regular JavaScript patching the real DOM, and transport is plain HTTP (POST + Server-Sent Events) - no canvas rendering, no WASM. It uses Web APIs directly, and the goal is to make the whole Web API surface available from Elixir. The only thing being swapped out is the authoring language, same as with TypeScript or Elm.

How do you think things appear in the browser if they don't use web technologies?