Earlier quoted context omitted.
But the issue isn't ignored or back-burnered.
That was more directed at the F-ING SSL issue, but still, end of 2015 to have a feature that's considered standard nowadays and introduced 7 years ago? How much of the work that went into deprecating certs and removing obscure command line flags and setting up HTTP/2 (which isn't even really used by anyone yet) could have went into electrolysis?
Another thing to keep in mind is that patch notes are a list of user-facing changes, not a breakdown of where the engineering effort went in a particular 5 week release cycle. Removing the command line flag probably took an engineer an hour or two to do. In the same time frame, I spent weeks analyzing and fixing a variety of leaks that only show up in multiprocess Firefox, but none of that shows up in the patch notes.