There were always people who used vim with tmux as their IDE.
But until language servers, IDEs with built-in code analysis had a huge advantage. This stopped once LSP was designed and some language servers got mature. LSP was developed originally by VS Code and it is easy to see why - it allowed VS Code to compete with IDEs without writing their own code analysis by letting language developers write a standard server. This made VS Code (and others like Zed) so powerful, that they had already replaced IDEs for many users (maybe outside Java). LLMs are just another nail in the coffin.
But until language servers, IDEs with built-in code analysis had a huge advantage. This stopped once LSP was designed and some language servers got mature. LSP was developed originally by VS Code and it is easy to see why - it allowed VS Code to compete with IDEs without writing their own code analysis by letting language developers write a standard server. This made VS Code (and others like Zed) so powerful, that they had already replaced IDEs for many users (maybe outside Java). LLMs are just another nail in the coffin.