Chrome and Chromium has flags to disable JIT as well, but there is definitely a significant performance penalty.
One area of greatest concern for me is client hints and the various JS APIs that leak way too much, from OS to memory and more. You would think that an extension as popular as uBlock Origin would exist that would make this information as generic as possible to mimic the most common browser profile. Without it, it is still incredibly easy to identify a user with JS enabled and unfortunately disabling JS also makes you unique.
This doesn't even address the Canvas API issue that needs to be virtualized to protect privacy. The web standard as a whole hasn't really put a lot of thought into privacy.
One area of greatest concern for me is client hints and the various JS APIs that leak way too much, from OS to memory and more. You would think that an extension as popular as uBlock Origin would exist that would make this information as generic as possible to mimic the most common browser profile. Without it, it is still incredibly easy to identify a user with JS enabled and unfortunately disabling JS also makes you unique.
This doesn't even address the Canvas API issue that needs to be virtualized to protect privacy. The web standard as a whole hasn't really put a lot of thought into privacy.