Yeah, that Cursor blog post is a bit iffy since they just brush over the "ripgrep is slow on large monorepos", move on to techniques they used, and then completely ignore the fact that you have to build and maintain the index.
On a mid-size codebase, I fzf- and rg-ed through the code almost instantly, while watching my coworker's computer slow down to a crawl when Pycharm started reindexing the project.