their budgets are SO extremely deep and large. And this cap? This cap is the best they could come up with?
You're assuming that there was an expensive program to replace the entire bottling line and redesign the bottles in order to meet the EU regulation while achieving satisfactory user experience.
What likely happened is that the engineers in charge of the cap design were told to change as little as possible and came up with a design that only required changing the cap moulds. Everything else got to stay the same, saving the company's budget for other things