Having myself not worked with React, I think it’s a more common pattern than you think to re-render/rebuild an entire section of a page to reflect small model updates. It’s a less error prone but less efficient way of maintaining consistency. Virtual DOM exists to help make that exact sort of thing more efficient.
Virtual DOM is an abstraction that provides reasonable performance for less effort. You can always get more performance by bypassing the abstraction, but at the cost of more work and complexity.
