The trouble is that it’s users that are burned by this, and only a subset of them, so the developer doesn’t notice unless it affects their particular usage patterns.
But if you have things like “I put my button inside a form, and now when I click on it the page reloads” (because it’s now a submit button, so you need to either change it to type=button or add event.preventDefault() to your click handler or form submit handler, according to taste), that’ll affect everyone, and thus you’ll notice it immediately, and thus it’s you as a developer being burned by it, and so you notice it.
I see; pretty much the same reason a common problem is that only the happy path works properly - that's the thing for which it's inherent to the development process that it gets tested.
But if you have things like “I put my button inside a form, and now when I click on it the page reloads” (because it’s now a submit button, so you need to either change it to type=button or add event.preventDefault() to your click handler or form submit handler, according to taste), that’ll affect everyone, and thus you’ll notice it immediately, and thus it’s you as a developer being burned by it, and so you notice it.