Here's another reason why browser extensions can be incredible and why the browser continues to remain the last bastion of control for the user: Reddit comment replacer.
It replaces your reddit comments older than a certain number of days with a text you want. This is going to really muck up training based on the content that reddit's licensing to Google (now) and any other scrapers using this data to train their LLM.
Am I recommending you do this? No
Is this really cool and showing you the power of the web and why we should all embrace it? Yes