I can tell for you specifically because everything is specific: machine, hardware, setup, projects...

But I always noticed this latency for everyone I ever saw using vscode or computer that I tried.

To be clear, you might easily not notice it if you are used to that and don't know better. And it is consistent with most electron based apps or editors. But there is a very subtile latency between the time you hit the key in the keyboard and the time that it appears on screen. Basically you are typing letters a little bit in advance. With Kate it is like with a basic text edit, characters appears instantly.

The effect is the same when you type anything in web browsers. In form, editor or whatever.