Well, I'm not sure what you're waving at. If the website is nothing more than a RTE, then it's better (and safer) to do it in the browser. If the RTE is just part of the website, then that's a part that's better done in the browser.

Perhaps you want a RTE that doesn't depend on JS. I think that's a reasonable thing to want; but if you normally browse with JS switched off, then running into a working RTE is at least going to violate the Principle of Least Surprise.