Genuinely asking, is having her as a federal judge better than having her continue to litigate cases? The article even says she's unlikely to see many of more important cases due to her representing a rather liberal district.
It depends. For example, depending on the situation, one could shop for them as a specific judge. That's a really unfair and immoral thing to do though, so nobody does that...
Federal rulings set a legal precedent and can then be used in future rulings. So all of her court decisions can/will be used in the future to convince judges to make similar rulings.