1. It's reactive security because you can still take action after your bitcoin has moved on chain. This does not currently exist in the bitcoin protocol. If your private key gets popped it's game over immediately.

2. Miniscript allows you to define far more flexible conditions that must be met to spend your coins. It doesn't mean improved security over the existing options, just that you can apply existing security measures in more scenarios. OP_VAULT adds a whole new layer to your security setup.