This article explicitly points out modern alternatives to PGP's clunky, 1990s implementation of asymmetric encryption.
But, tangentially, it's a bad idea to use asymmetric encryption when you don't absolutely need it. Modern symmetric AEAD ciphers, which are implicated in pretty much all serious public-key designs anyways, are safer to use that asymmetric cryptography.
Seeing a public key in a design that doesn't demand public keys is a cryptographic engineering code smell.
I'm not sure it's just me being behind the times, but it seems that quite a few of the ideas behind PGP (specifically: asymmetric encryption) aren't really being exploited seriously. Instead there's lots of halfhearted "oh, let's just encrypt thing X with a password stored in thing Y" where Y is presumably more 'secure'. This is a bit of a tangent, but I find it interesting and depressing that industry has learned very little, if anything.