If you use a webclient, it doesn't matter, you trust the server no matter what you use. Ots cli has the advantage of being auditable once, and remain on your computer.
True, I was thinking about the problem from a web only perspective, since WebRTC tries to do a direct connection between peers and only uses a third party server when one or both connections are behind a NAT.
If you initiate the session from your browser it doesn't matter. At best you get better cryto since it's native, but nothing more, and you can't store the result, so the receiver has to be connected.
If you don't, then the point is moot, and the problem has been solved with the excellent magic whormhole cli.