You run arbitrary code from a lot more sites than you just those you visit, and I doubt you're combing through it. Third-party JS, tracking, unblocked advertis

You run arbitrary code from a lot more sites than you just those you visit, and I doubt you're combing through it. Third-party JS, tracking, unblocked advertisements, possibly malicious on-site code, etc. If you're allowing any site to run JavaScript, you're running entirely arbitrary and uncontrolled code on your machine, and thus is in dire need of the mitigations. It's a different situation for a server designed to not run remote code, which makes it practically impossible to exploit speculative execution vulnerabilities.