I was curious why the page was so slow to respond, so I opened up my dev tools and did an analysis on where the resources were going. You can see things like which methods are taking up memory or cpu, or which ones take extended periods of time. You can also see how often the screen “repaints”, which is essentially how often the html is re-rendered. You would ideally only want to re-render the page when something has changed, and you’d want to batch your changes so you maybe have 1 repaint that updates 20 things, rather than 20 repaints that only update 1 thing. Repainting blocks user interaction and is slow, thus causing the slowness experienced.
Hope that made sense!