My wife and I are the same way. We have a common account that covers all of our bills, groceries, family night outings, etc. We each pay our own car payments if any, car insurance, etc. We both have expensive hobbies that have caused issues with partners in the past, so our personal accounts are our individual fun money accounts.Can't speak for others, but it's never been an issue with me and my wife. If both people are responsible then I don't see the issue in choosing to do so. We do have one joint account in addition to our separate accounts.
We were both financially sound coming into this and already had our investments for retirement in place. We went over everything and have no financial secrets from each other. We have access to all accounts, but have no need to look at each others as long as we are both well and above ground. It provides us each with a little bit of freedom from judgement when I buy another gun or more parts for a car that runs perfectly fine the way it is. I know there are plenty of situations where this would be less than ideal but it has worked for us even several years before we got married but cohabitated.
We do thoroughly discuss all big purchases even if we are paying for it out of our fun money accounts. I think that part is important so the other person knows it has all been budgeted for and will not impact our joint funding.