Not disagreeing with your comment, but IMO this is just another historical accident. GUI programming exploded together with OOP, and a lot of libraries/toolkit

Not disagreeing with your comment, but IMO this is just another historical accident. GUI programming exploded together with OOP, and a lot of libraries/toolkits were made when using OOP was almost mandatory. As much as frontend programming gets a lot of flack, functional reactive is a much better paradigm. One can however argue it's just lacking better implementations for non-web applications.