Medical expenses may be automatically billed back to the insurer in the UK however flights, hotels etc it’s the same as the UK. You have to pay and claim back. This can be rather expensive (last year we needed to pay £12k in that connection, all eventually reimbursed) so one of our cards we bring has a high unused limit.
I can’t see any valid reason in this day and age in many parts of the world not to use cards. And certainly I do as asked at check in to avoid delaying others behind. If they ask for my card, they get it. I saw someone decline to do so in Norway and the whole checking in got stuck with supervisors needed etc