The issue is that on regular projects/products, you are trying to hone on perfection by adding and removing a bunch of things and trying different stuff. This r

The issue is that on regular projects/products, you are trying to hone on perfection by adding and removing a bunch of things and trying different stuff. This repeats for a longer period of time, say 6 months to a year. The codebase has got to be able to survive that churn in a sensible way, and certain tools like (ES6) modules, types and declarative UI descriptions that automatically update to reflect the changes really help with this process. Why does this declarative approach help? Because the more features you add, the more places can generate events that cause updates to the same DOM, and the number of possible transitions between those DOM states grows a lot larger. If the number of possible states that the DOM can end up in is N, the number of possible transitions is N^2. To a first approximation, declarative frameworks scale linearly with the number of interacting features, while imperative (the vanilla DOM API) scale quadratically.