I see that 50% of people in Belgium have credit cards and I suspect it's because bank cards until very recently used to be almost only usable in Belgium, and not for online purchase (except at some Belgian stores). So you would need a credit card for a "normal" modern online life.

Not sure if it's still true but it also used to be the case in Canada while I lived there a decade ago or so.

Bank cards today seem to be double more and more as Mastercard/VISA debit cards and I think the amount of people bearing credit cards might decrease in the future. At least that's what has been happening with a few people around me.