Earlier quoted context omitted.
This practise is illegal in the UK and that's probably why they decided to this instead
It's illegal everywhere in the EU as well. If a merchant accepts debit/credit cards then they are not allowed to charge extra for using them.
Example in English: https://www.flysas.com/en/help-and-contact/faq/booking/why-d...
And in Danish: https://www.tivoli.dk/da/om/vilkaar-og-betingelser/betalings... (or without the reasoning in English: https://www.tivoligardens.com/en/om/vilkaar-og-betingelser/b... )