It may not be much easier than your setup, but my fiancée and I have a shared Simple account that we both deposit $x to each month and then withdraw shared transactions. They make moving between shared and individual Simple accounts pretty easy and allow bucketing money into categories, which we use for various budgets (travel, restaurants, groceries).
For us, we like that the budget is tangible. There is only so much money we can withdraw from it, which helps us avoid blowing through our budgets. It also works well with the way we split costs. I make more money, so I put more into the pool every month, but other than that we don't need to think about it.
This looks bad for Google. EdgeSpot detected an in-the-wild exploit and told Google about this in December, but Google wasn't going to fix the bug until late April.
Google only released a patch early because the finder blogged about it.
Generally, it's the responsibility of whoever made the changes to resolve conflicts (basically, git blame conflicting lines and the people who changed them get notified to resolve conflicts in that file). Distributing the work like this makes the merges more reasonable.
For us, we like that the budget is tangible. There is only so much money we can withdraw from it, which helps us avoid blowing through our budgets. It also works well with the way we split costs. I make more money, so I put more into the pool every month, but other than that we don't need to think about it.