Vim can jump to definitions and stuff too. It integrates with ctags. It can also do code completion and everything else. I have it bound to clang-format with ctrl-k.
Heard good things about it, but I'm on an endeavour to learn how to do things with Vanilla Vim first to avoid abusing my use of plug ins for things Vim can handle gracefully ootb.
Now you're the creator of autojump, I just want to say your software is definitely a time saver, especially with this https://github.com/fdw/ranger-autojump, keep up with the great work.
I'm with you with avoiding too many plugins. But LSP is not just another plugin, it's the standard for languages to implement IDE support. I find it hard to justify not using it if you're doing serious software development (depending on the language of course).
Thanks for the kind words on autojump :) I'm no longer involved with the project, but I feel the general idea is still relevant.