It is a significant deal. She wasn't alone in doing so (her predecessors had engaged in similar behavior to a degree as well). What's interesting is that the heat and light about it wasn't followed by any legislative/policy action of note. It's almost like they weren't trying to right a wrong, but to politically assassinate her.
The sitting president communicates on an unsecured iPhone. The WH staff is using alternate email systems and messaging to actively avoid leaving a trail.
Let me know your concern about that and I'm happy to continue this conversation. Otherwise, you're engaging in partisan politics here and that's not good for HN.