I don’t know if this is true in general, and in fact our money styles are quite similar now, but my partner and I came into this relationship with completely opposite money styles. I was frugal to the point of obsession and he was extraordinarily generous and had some bad debt with a terrible credit rating.
To be fair, I was working my way through uni, supporting myself by working 3 low paying, casual jobs and studying full-time. I got a discount on my uni fees by paying upfront. It was around $8K pa - live in Australia and our unis are govt subsidised - but still a huge chunk of my savings and income. I really had to be a little bit obsessive to survive.
My partner spent money like it was going out of fashion, was constantly shouting his friends things like expensive meals and, because he never had money, had the perception that his spending was low, and that he was frugal. I think he thought that he was good with money because he could afford things like paying for nice restaurants, he really didn’t associate the downside.
I was monitoring my spending using a home finance package but could not convince him to participate, much to my frustration, he felt he was good with money - he just didn’t make enough… Eventually I just took a 3 month dump of his bank statements, split it into ingoings and outgoings, put it in a chart and showed him “this is what you make each month, and this is what you spend, and this is what I make each month, and this is what I spend”
He was soooo shocked when he realised how much he was really spending and he has pretty much let me run the finances since then (I am an accountant BTW). I don’t restrict his spending, he actually is pretty good with that, but if he starts going crazy I’ll gently let him know he needs to pull up and, after a little resistance, he does.
It’s definitely not a one-way street though, he taught me that it’s ok to spend money to increase your quality of life now, that you can’t delay all gratification. Without him I’d be living on baked beans in a shoebox, would never holiday, would rarely buy new clothes. I think I still have some stickers from when I was a kid which were “too good to use” (not a hoarder, it’s just a random sheet that got caught up in my filing) We do have a cleaner, once a fortnight - which is a quality of life thing and for us totally worth it. It costs a little over an hour of work (yes I do that too).
So I guess now I see balance as a good thing, and I do think we’ve both improved our quality of life through learning from each other. I guess you really have to be willing to learn though, if either of us had just dug in then there’s no way we’d still be together.