Out of interest, what language are your projects written in? I've had to work on C# .NET codebases of that size and have had the same issues as the previous response.

VSCode itself doesn't fall over, but code completion and error highlighting are painfully slow to catch up and several of the extensions that provide that functionality regularly crash out.

I work in multi-thousand LOC projects in TS in vscode. It lags.

It LAGS a lot. I work on Xcode Swift projects and the difference is amazing (and Xcode is quite crap). Auto-complete or sometimes just opening a file takes seconds. (I know my project has a bit more complexity that a normal react/node app, but still...)