I'm the main earner in our house and have been for a couple of years. Before that we worked equal hours and earned about the same.
In our case, we made a joint decision to reduce my DH hours. His job is just that, a job. He's been in it a long time, and it's completely stable, but it's going nowhere and his earning capacity is limited.
My job, on the other hand, is senior in a small company which is growing rapidly and has the potential to mean he could quit work altogether in a few more years. I currently earn twice what he does.
The trade off, though, is that I struggle with time off, particular short notice adhoc stuff for school. We both felt it important for DD to have someone who could go to things like that, and our current arrangement means we don't need childcare during termtime, and only need a couple of days each week of the holidays.
It's not been plain sailing, and there have been times when I've felt he's been taking the piss a little bit with lots of trips a week to our local coffee shop after school where he also goes to play card games rather than doing the larger share of housework we agreed as part of the arrangement or doing things for and with DD, but we've talked about those and sorted it, and it mostly works fine.
Our bank accounts are joint and always have been and I manage the finances in terms of bills and such. He has a spending money account which is his to do with as he pleases