ubrowser? Looks like there is a package for ActivityPub, not sure if lemmy has integrated by default the Mastodon API necessary to use it or if someone will have to hack something together on your instance. https://codeberg.org/martianh/mastodon.el
Thank god I was joking.
As a GNU guy I also feel the need to apologize for point you to a website that uses non-free JavaScript.
remember the old emacs vs vi holy wars? lol
vi vi vi is the editor of the devil :-)
i'm a vim user and i 100% agree with this. lol