I'm using a 5K iMac with Radeon Pro 580 8 GB. I'm making the comparison vs Sublime Text which has no lag and is my standard. This is based on my experience, not benchmarking, just try it side by side and you'll see.

My Sublime Text is decked out in plugins and so on too, there are instances where it slows down but only when it's obviously doing some processing. The basic rendering is fast, totally unlike vscode. But like I said vscode is still "fine" just uncomfortable.