Why do people still use emacs and vim in this age of VS code and intellij?

I’ve heard plenty of arguments, but they kind of suck to be honest. They’re more like rationalizations for why they stick to what they know.

I just don’t get it. Why use inferior tools?

Both are lighter weight. Big deal, buy a faster computer. It’s nothing compared to your salary.

Both may let you type slightly faster and move around faster. Maybe. But that’s not the bottleneck anyway.

Why? Am I missing something or is it just an irrational attachment to software they learned long ago and prefer to stick with rather than learn something new?

You seem to be missing that they're not actually inferior tools. I can't think of a single thing that can't be done at least approximately as easily with emacs than with VSCode and the like.

Are they really? Do you get all the same plugins, all the lints and hover info, refactoring, jump to usages/definition, smart auto complete, etc?

They seem awfully limited to me by comparison.

https://github.com/neoclide/coc.nvim

Or

https://github.com/neovim/nvim-lspconfig

https://github.com/hrsh7th/nvim-cmp

No different than installing plugins in VSCode for completions, they all work via calling out to a LSP server using https://microsoft.github.io/language-server-protocol/

When you don't understand something it's only natural to be unaware of its capabilities, yes.