Not much. I don't use any bundles myself and never have FOMO. I sometimes copy configurations from big projects like Chad and Lazy if I see a clever way they added in certain visual aspect (bufferline, statusbar etc.); one can also see their plugin list for ideas. I figure by doing it yourself, it's easier to maintain and learn the plugin functions/keybindings that way. The approach I take is (1) learn default nvim -> (2) understand what each plugin adds to the default functionality -> (3) install and tweak what you need to create your own ecosystem. But maybe it's a bit geeky and time consuming.
TL;DR: you're not missing out much, check in with recent commits from different projects if you want to steal new ideas, or just hang around neovim communities.