It's been my experience that extensions don't 'break' (i.e. stop working as expected) as much as they self validate against the currently running version of FF and refuse to load unless the developer has flagged it as workable.

Every time a major release comes out, half of my plugins are disabled. Then, I go and download the compatability reporter plugin (which gives you the option to override the version check), and 9 times out of 10, every single plugin works fine.

Also, what did you mean "how Chrome hides everything"? I'll admit the plugin system isnt near as robust, but for web development, I'm in passionate love with the Chrome/ium developer tools.