She has already ruined her legacy, much like Ruth Bader Ginsburg did. Fortunately, she doesn't seem to have caused as much damage (yet) as RGB did with her clutching onto power until death.
It’s never going to happen. She’s the deciding vote on the judiciary committee. Without her it’s deadlocked, which means no more federal judges. You can say what you want about how how terrible it is that she didn’t retire decades ago and I’ll agree with you wholeheartedly, but I’m not sure I even want her to retire if it means no more sane judges get confirmed.
In case it isn’t clear. Her Congress seat can be filled, but the committee seats she holds need to be voted on, and it can be filibustered. The GOP won’t let Dems reassigned those seats to another Dem; they’ll remain open until next session.
This is an excellent question, haha. At the start of the session, they’re voted in all at the same time. So if anyone thinks to filibuster, they’re also blocking their own seats. In fact, during normal operation, this process is done using “unanimous consent”. They don’t even bother with an actual vote because it’s always unanimous, because it’s all or nothing. If feinstein retires, the vote to fill her seats will be only for her seats.