The option to have baked-in privacy to a widely-nostr client is significant. 

Without this, users are dependent on making sure they have an always-on VPN (or Orbot) enabled. Otherwise your IP is shown to pretty much every relay, all the time. Needless to say, terrible for privacy, dealbreaker for anonymity (think journalists under oppressive regimes).

The always-on VPN can be unreliable on mobile devices. Orbot slows all your web traffic and some websites/apps block the traffic entirely, so many people disable it (to do mobile banking, or just get on Reddit, for example) and don’t always remember to turn it back on. Just a host of opportunities for it to be a problem unless you’re meticulous about it.

Granted, one probably needs to enable Tor in Amethyst the first time around, unless the default setting is on (Vitor, could that be the default?), but still, this is a big step toward privacy-by-default in freedom tech tools.

There may be another impressive quality of this, having to do with being able to send events to relays over Tor regardless of whether or not the relay normally accepts Tor connections. I don’t know (because I haven’t read the spec and likely wouldn’t understand it, if it’s all code, anyway), but by the wording of the OP it sounds like there may be something to this as well.