My wife and I have had separate checking accounts for 20 years, and a shared savings account, and a second shared checking account we use strictly for transferring money back and forth (we can’t use savings for that due to stupid banking rules).
We also have split the hills according to our relative incomes. I make a lot more so I have the mortgage and a few big ticket items, she has several of the other bills plus her own car payment.
We make joint decisions on big things like vacations, or more recently, private school for our kids.
I know other couples do it completely differently. Some have totally shared accounts. I know husbands on a strict allowance.
Do what works for you.