Sadly age is only tackling one of the easier parts of gnupg, encrypting files. Implying age replaces gnupg is overselling it.

We don't have any good alternatives for a web-of-trust (or something akin) where we can sign files or attest trust to some identity. Signify does parts of this, but lacks the trust aspects which makes you establish convoluted key distribution schemes to ensure you have future signing keys lined up.

There isn't any good replacements for F/OSS developers that needs to have some from of signatures between them. Say replace linux distributions usage of signatures to form some network of developer trust.