SimpleLogin is hosted with Protonmail and should be viewed as an extension of it. Proton cooperates with thousands of law enforcement requests and should be viewed as a corporation and not a just open source software that’s just code.
On the other hand, AnonAddy has a better UI, better reputation, seems like just 1 developer which is more hipster, Greenhost is a more trusted host by me, and is more representative of a FOSS project. You can self host it, and F-Droid has apps for it by different random developers. SimpleLogin uses Coinbase as a crypto payment provider, which blocks Tor and is going to get the transaction run through an anti-fraud (and therefore anti-privacy) surveillance tool.
I do not support crime, I but do support a decentralized internet. Protonmail & Coinbase are more centralized than a lone hipster with Greenhost and Globee.
That's a great explanation and gave me some things to research 🙏