[low_battery]

I guess as long as it is not default behavior it will stay as a weakness then? I am not sure if it is worth to exchange it for memory or performance gain.

Also is using thread per tab approach more susceptible to memory leaks, resource sharing issues or OS scheduling shenanigans than process per tab approach? You close the tab, the process is dead and resources are mostly guaranteed to returned. My knowledge of modern browsers is limited, maybe this was considered an acceptable compromise though.

[willtim]

Perhaps that now they are using Rust instead of C++, leaks and memory corruption should be much less of an issue.

[kibwen]

Though the Firefox developers aren't going to skimp on sandboxing (or other exploit mitigation techniques) just because of Rust. Defense-in-depth is the name of the game; Rust just provides a layer of language-level defense that C++ previously didn't offer.