> a large portion of the frame time in that demo is spent in browser code, recalculating styles and redrawing
This was my point actually, not that React adds no overhead which of course it does.
Updating a property on a bunch of DOM nodes, without actually waiting for their effects to be applied by the browser, is of course very fast. But the browser code (reflow, paint, etc.) is part of the frame budget, and the number of nodes you can change – accounting for those changes actually appearing on screen – within that budget is embarrassingly small regardless of whether you are doing raw DOM operations vs. using a framework like React.
It doesn't really count to say "ah yes, but the code that technically made the update was fast!" when the updates haven't actually been committed to the screen yet.
This was my point actually, not that React adds no overhead which of course it does.
Updating a property on a bunch of DOM nodes, without actually waiting for their effects to be applied by the browser, is of course very fast. But the browser code (reflow, paint, etc.) is part of the frame budget, and the number of nodes you can change – accounting for those changes actually appearing on screen – within that budget is embarrassingly small regardless of whether you are doing raw DOM operations vs. using a framework like React.
It doesn't really count to say "ah yes, but the code that technically made the update was fast!" when the updates haven't actually been committed to the screen yet.