When there are no laws regarding it, it is quite simple: you add the prominent end subscription button. When you are dealing with the laws of one jurisdiction, you (or your lawyer) review the law to ensure you meet the definition of prominent, are using the correct language, etc.. Multiple laws in multiple jurisdictions: not only is it more time consuming to ensure compliance, you better hope the laws don't conflict (otherwise the complexity of the solution is going to climb rapidly).

I see this same argument presented by grandparent trotted out when people argue against including tax and fees in the price in the States. Australia and NL manage this just fine, and somehow multinationals and small businesses manage to conduct business that follow these regulations in these countries while still dealing with a patchwork of country and region specific enforcement regulations. And the example I gave is more difficult than adding a cancel subscription button.