Rabb.it (https://en.wikipedia.org/wiki/Rabb.it) did this some years ago. It was an amazing service, but it unfortunately shut down. This is very close to what it was back then.
The watch party website is still up at https://watch.hyperbeam.com, we're the biggest Rabb.it alt that offers virtual browsers.
Without Rabb.it, we wouldn't be here haha