It’s a bit of flair that can be handwaved away. Unlike back-end systems, where due to the non-visibility, flair isn’t exactly seen, the best way of being tongue-in-cheek is a dud API or a comment highlighting some strange behaviour. But front-end is more visual, which is why designing how to animate your hamburger menu button is just something you might end up doing.

It’s not necessarily bad, trying to add a little animation or complexity, if it’s not in-your-face: it can help vary style, experiment with what clicks with an audience, and develop skills. It can also act as a status signal for the website if it can afford for developers to fine-tune every detail – Apple is a good example here.

But yes, the best design is usually one of the simplest ones. Some designers try to make content glide over your eyes and forget that this doesn’t fit usability needs.