Over the past couple of months, since the release of WordPress 5.0 which includes Gutenberg, the new JavaScript-based block editor, I have seen many sites loading a significant amount of extra JavaScript from wp-includes/js/dist on the frontend due to plugins doing it wrong.
So dear plugin-developer-friends; when adding Gutenberg blocks please differentiate between editor access and visitor access, only enqueue JS/ CSS if needed to display your blocks and when registering for front-end please please frigging please don’t declare wp-blocks, wp-element, … and all of those other editor goodies as dependencies unless your 100% sure this is needed (which will almost never be the case).
The performance optimization crowd will thank you for being considerate and -more likely- will curse you if you are not!