As of 4.1 web exports still have some limitations due to poor vendor support of certain modern features. Browsers with bad WebGL 2 support, such as Chrome on macOS, unfortunately suffer from issues which we cannot address without a fix from Google or a significant amount of effort put into supporting a dedicated WebGL 1 / GLES2 renderer.
We are also aware of the complexity setting up web games on hosting platforms which don’t let you set the required CORS headers for SharedArrayBuffer support. This mostly depends on Safari implementing the coep:credentialless header support, while Chromium-based browsers and Firefox already work fine (especially if you publish on itch.io). There is a possible workaround that we are investigating.
Nice to know that they're aware of all the web issues. As someone mainly using web exports it reaaaally hope they get around to fixing compatibility issues on web exports, and hopefully removing sharedarraybuffers being required.
As always, I blame Apple :P