I'm the sole earner in our family. My wife has been a stay at home mom for the last 7 years and I wouldn't have wanted it any other way. It was particularly wonderful during the pandemic - we pulled the kids out of the school system and had great success with homeschooling. (Obviously there were plenty of challenges and difficulties, but overall a great experience).
I make a bit under 150k a year which is pretty good in our area (although it certainly _feels_ like we should have more money than we do, guess that's life for you). All our regular expenses fit into about 5k a month.
There is about an extra 400 per paycheck after we budget for savings, which we divide into two separate checking accounts. These are our respective "fun money" accounts, and that money is off budget and purely discretionary. Hers goes largely to coffee and books, mine goes largely towards fishing, weightlifting, and guitar stuff in various percentages depending on what I'm most into at any given time.
My wife is planning to start working part time eventually - this is the first year when both kids have been in school full time. This money, in theory, will fatten up both savings and discretionary cash.
It has worked out pretty well overall. We budget the "regular" money with reasonable strictness, and the "fun" money makes it easy to keep our hobby spending from digging into the important money.
Minor edit: We have never thought of money as belonging to either one of us, even when we were dating in college (I mean, at first we did, obviously, but after a two or three years it became moot). We're a team, the money that comes in is _ours_ - not mine.