I have a joint credit card with my wife. Nearly all transactions go through the card, so the bill is around 3~4k per month. It is automatically paid from our joint current account each month. We get cash back so it actually makes us money, albeit a very small amount, think 20€ per month.
However, it is very handy as it insures any purchases, and if something happens it is easy to lock the card, or get a refund from a retailer. With the itemised statement and App, it is easy to track spending. I'm lucky as neither of us are impulse spenders, so that issue doesn't arise.
It might seem a lot per month, but I mean all purchases go through card. Think groceries, petrol, eating out, esb, oil, car insurance, house insurance, Christmas gifts, holidays etc. It's amazing that there always is at least one big ticket item each month.
It also doesn't leave our debit card, with it's access to our current account, open for fraud etc.
We both also have personal Revolut accounts (personal as it's in our own names, we share all finances so there is no hidden expenditure etc.) I use the one-time Revolut virtual card for any websites where I'm in any way worried about hacking etc. Also handy as a backup on holidays is something happens to the credit card where it is either locked (don't ask!) or stolen.
We have debit cards on our current account but they are rarely used, maybe once a year.