Q: Why browsers can't get a newer/different programming language other than JS?

I have wondering, since there are a lot of efforts going on improving JS or to support webassembly. Why it's in that direction?

Another direction would be, making browsers use hardware resources, like apps can do on smartphones, or basically like any other software, Or maybe probably completely support a whole new language that would be built specifically for frontend needs other than JS?

Is that not possible? is this why the efforts are going into the JS/webassembly direction?