I think it's reasonable to trust Firefox's privacy more than Chrome's. But there are very few people in the industry who trust it's security more than Chrome's. Chrome has a more secure architecture and one of the best security teams assembled for any consumer product.

The iOS and Chrome recommendations are the things I'm saying that I believe to be somewhat unpopular here. But in the software security community, they've been commonly accepted for several years now.

I try not to recommend PGP anymore, not because it's unsafe but because it's difficult to use and discouraging for unsophisticated users.

Having said that: I actively warn against trying to use PGP for secure email. Email has inferior security even with PGP layered on top of it. Signal was designed for long-term asynchronous conversations; if you can use PGP, you can use Signal. Use Signal instead.