Sorry could you elaborate? You just linked to the MDN page in the comment and claimed it was bad in that one. Did you mean to link to a different one?
It's implemented everywhere, so it's not that it's a single browser doing something weird, it seems to be sandboxed (in a conventional sense), and there's plenty of use cases where an application might need high performance storage access or a pseudo filesystem.
What is your reasoning for unimplementing it rather than mitigating the issue? I don't believe there is an equivalent web technology to this that people could use instead.
I get that the paper has discovered a flaw, but I don't see how it is unmitigatable, it's still a sandboxed filesystem at the end of the day, rate smoothing and noise insertion seem like fairly obvious first steps and I'm far from an expert.
It's like saying we should get rid of VPNs because they suffer the same kinds of side channel risk.