I think this probably depends at lot on language. I mostly code in Rust, and for a simple example of one of the "most basic refactoring steps", renaming a type/function/variable/etc. and updating all the uses work quite well using rust-analyzer. I'm not doubting that Intellij might have a lot of nice refactoring features that VS Code doesn't, but I'm definitely able to do a lot more than just regex searches.
I use both vscose and intellij, and I must say that even though vscode can sometimes feel snappier without any plugin running, it's missing a whole lot of features even with dedicated Microsoft plugins running, to the point it feels half-baked. I'm talking about things like basic refactoring support and even symbol recognition.
IDEs like intellij and Clion may have slightly longer startup times, but that doesn't really matter as you're only going to start the app a few times throughout the day.
Ultimately vscode is nice if all you want to do is open text files and Run regex searches, but the minute you want to run the most basic refactoring steps then it's faster and less frustrating to just start intellij, refactor, save files, and quit the app.