Unfortunately web browsers don't support it, so it requires an external client to download.
The goal is basically to not have to use the bridge in the future.
Also one plus with a bridge compared to just downloading directly is that if a file becomes popular your server does not need to shoulder the full load since the webtorrent swarm can handle most of the load.
I guess I'm old, but it used to be common to - gasp! - install multiple applications. Now, the browser is basically everything.
Also, Opera used to support torrent downloads.
Try it.