Dropdown, navigation button, tooltip, collapsible panel, lightbox, tabs, switch like above…
And for what? Again - there is a swath of use cases which would be hard without React and which aren’t complicated enough to push beyond React’s limits. But there are also a lot of problems for which I can’t see any concrete benefit to using React. Those are things like blogs, shopping-cart-websites, mostly-CRUD-and-forms-websites. For these things, all of the fancy optimizations are optimizations to get you closer to the performance you would’ve gotten if you just hadn’t used so much technology.
As a matter of fact, the Time To Interactive does not measure how long it takes for a page to become interactive, it measures how long it takes to be sure, regarding the conditions, that a interactivity can happen in a satisfactory way, for at least 5 seconds.
"For most developers, code caching should “just work”. It works best, like any cache, when things stay unchanged, and works on heuristics which can change between versions. Nevertheless, code caching does have behaviors that can be used, and limitations which can be avoided, and careful analysis using chrome://tracing can help you tweak and optimize the use of caches by your web app."