You're missing the point: SimpleX is easy to break by governments.

Think for a bit: there is only one realistic way to use SimpleX for normal users and that is through the official app by the original author.

99.9% of those users will open channels on the same servers hosted by the original author.

The original author has received VC funding, large part of it by personalities with a track record of government cooperation. VC-funded companies need to provide return to stockholders, governments tend to pay for access into those apps (e.g. Signal received +30 million per year from the CIA until recently).

Now go back to the first paragraphs: you are using the author app and servers. It is simple to give you a spoofed version of the client app that makes you write in plain text or share those text with some federal agency. It is standard practice to give modified apps to PoI targets like you, and you won't really find the difference.

You should NEVER make it so easy and use the author app nor servers for that exact reason. That is why NOSTR is great, has hundreds of volunteer relays that make difficult to track incoming messages and dozens of different clients to retrieve them that are E2EE without cryptographic doubt.

From an adversarial point of view, NOSTR is 100x more secure than SimpleX. This is obvious to anyone working on that kind of industry.