I actually made an extension that hides the AI results (using a different method), and which works across Google, Bing, and other search engines. [1]
It's 100% free (of tracking and cost).
1: https://chromewebstore.google.com/detail/beeline-search-avoi...
Yeah, we are still needing a way to modify webpages. Hiding a div on a web page is about ~1 line javascript, and there is no way to inspect and share it.
Extensions are a security risk, userscripts are a security risk as well. Too bad all the current browsers are user antagonistic :|