Sure, 10ms vs 40ms is measurable, and for the keen-eyed noticeable. But if you're only pressing the button once every 5 minutes, it doesn't matter. Similarly, if the button triggers an asynchronous call to a third-party webservice that takes seconds to respond, it doesn't matter. And so on.
Of course, for the things where users are affected by low latency, we try to take care. But overall that's a very, very small portion out of our full functionality.
Sure, 10ms vs 40ms is measurable, and for the keen-eyed noticeable. But if you're only pressing the button once every 5 minutes, it doesn't matter. Similarly, if the button triggers an asynchronous call to a third-party webservice that takes seconds to respond, it doesn't matter. And so on.
Of course, for the things where users are affected by low latency, we try to take care. But overall that's a very, very small portion out of our full functionality.