Absolutely can agree with what you're saying. I was just trying to highlight the effects such a common arrangement can have when it's not sustainable. My annual income was about $10-15k, his was 6x as much.
I neglected to mention that the 50/50 wasn't the original agreement, it was 75/25. In return for it not being 50/50 it was agreed that I would do all the household chores (cooking, cleaning and taking care of the bills etc.)
He played his trump card so many times we ended up just creeping in to a position of it being 50/50 because it was being held against me. I was still doing all the chores. (He'd argue about loading the dishwasher when it was his turn, despite me cooking him a dinner every night - hence why I called him a narcissist).
I was just trying to post something that may provoke thought for others that may be in a similar situation that may not be seeing any red flags because they are blinded by love.
If you are in an agreement and it works - great. But if the tables start to change, it's easy to go along with it when Oxytocin and love are involved.
It's torture when you consider the fact that one partner can not expect the other to live the same lifestyle as them if there is such disparity in income if the one earning more is not willing to provide the lions share. He wanted holidays, to go out and shop at the most expensive supermarkets but was not willing to pay more - that was the torture.
The infidelity is not 100% relevant; I guess I just understand his lack of commitment to joint finances is akin to his lack of commitment to me.
I hope that explains the reasoning for how I worded my original post. I agree that my writing was emotive, but that's because it's a personal experience I have had to go through where that financial agreement situation did not work out.
My post was not meant to be an attack on a 50/50 agreement, merely I was highlighting a consequence, albeit probably uncommon, of why it may not be the best way forward if there is a considerable difference in income between each half of the relationship.