You might be right, but I trust random webpages to be sandboxed by the browser and the rest of the stack to be kept in line by reputational concern or peer vett

You might be right, but I trust random webpages to be sandboxed by the browser and the rest of the stack to be kept in line by reputational concern or peer vetting. Using some dude's userscript that I found online doesn't have any of those guardrails.