A Veritasium video about the topic, if someone is actually interested: https://youtu.be/9cNmUNHSBac

I use fx_cast extension, it’s been working great for years. Although it needs the “bridge” to be installed, which is some minimal headless chromium thing.

It’s not a seemless experience, as it has a domain whitelist enabled by default, so you need to mess with it in the extension settings first, but once it’s been set up, it’s fine.

Sometimes it can mix up old/expired sessions, so the website would say you’re casting but you’re not. You can just press the “active” cast button and disconnect, then reconnect again.

Some other times (rarely) it fails to mock the casting feature and you won’t see the cast button or it would be disabled. Refreshing the page helps. If not, double check your whitelist.