Hey, good question actually. After more digging the issue clearly seems to be some add blocker extensions that are on by defualt with Brave.
/html-callback net::ERR_BLOCKED_BY_CLIENT
(anonymous) @ htmlgame.js:1
(anonymous) @ htmlgame.js:1
Ts_Bhj7_Pxlmw.js:452 Godot Engine v4.6.stable.official.89cea1439 - https://godotengine.org
Ts_Bhj7_Pxlmw.js:452 OpenGL API OpenGL ES 3.0 (WebGL 2.0 (OpenGL ES 3.0 Chromium)) - Compatibility - Using Device: WebKit - WebKit WebGL
Ts_Bhj7_Pxlmw.js:452 Build configuration: Emscripten 4.0.20, single-threaded, no GDExtension support.
This confirms that 1) it is indeed running in compatibility mode and 2) Its being blocked by the client (my browser). Weird though, cuz ive never had this issue before.
But the issue is totally with me and nothing to do with the efficiency of your game