Suppose that all browsers hide javascript-inside-svg behind a preferences checkbox that's turned off by default. What on the web breaks? Most of the scripting

Suppose that all browsers hide javascript-inside-svg behind a preferences checkbox that's turned off by default. What on the web breaks? Most of the scripting related to SVGs I've seen are SVGs controlled by javascript in the containing HTML, usually through an HTML framework. Hell, in the history of the web has there ever been a framework written specifically for the javascript-inside-svg case? The irony is that svg has not gained generally usability as an uploadable image format precisely because of this feature that nearly no one uses.