because React's stance is that it's a rare enough case in their experience, so they don't spend time optimizing for it.

that metric is slower in general because libs with simple reconciliation strategies will tend to do work for every row between the two swapped ones (2,998).

So what's the benefit of more complex ones like react's?

By choosing React I'm optimizing for my time. I'll always add a framework that adds a tiny performance overhead if it means I can develop and maintain features easier.

That said -- performance characteristics like this are rarely interesting to me. The vast majority of "performance issues" I've encountered have to do with high-level architecture and/or network issues. I've never given up on a framework because it couldn't swap two DOM nodes fast enough.

I was surprised by the delay though, 500 ms for swapping nodes?

Popularity.

The ecosystem is bigger and there are more devs available.