Saving or building, which is more sensible?

Whether 3 accounts or one, it's the same thing, right? Suppose your joint account always stays around +/-0 euros. Now a new car/vacation/etc comes up that should actually be paid 50-50. Then your wife says, "My account is empty because of pointless purchases and unprofitable sales, I can't contribute 50%" and then? The purchase doesn’t happen? Or do you pay e.g. 70-30? In case 1, I’d be annoyed if I were you, because then you can’t go on vacation or buy a new family car, etc. And in case 2, you’d be annoyed just the same because you have to pay much more than your wife, who lives on consumption. And then that’s it with “I don’t care what my wife does with ‘her’ money.” Unless, of course, you never have a money shortage. Or to put it another way, what are you saving for? Because you have to be saving for something, otherwise the 3-account system would be pointless, right? Best regards

puts it quite nicely too: it is an art to tolerate and avoid the flaws of the other, rather than constantly replacing people because of their flaws or simply getting extremely upset about them

Thanks for the compliments and yes, that is what I meant. And I am very surprised by the resistance to such a self-evident fact.

Due to many changing life impressions, variable possibilities and workplaces, a break, a separation, a divorce now occurs much more frequently. The SK can’t do anything about it, the stupid man or woman can’t do anything, that’s just how it is.

But I consider that only part of the picture. At least the generation of my grandparents here in the Ruhr area still followed a classical model: man worked shifts underground or at Thyssen, woman took care of the children and household. The men couldn’t operate the stove and wanted to shave with the vacuum cleaner, the women had zero personal money and zero pension entitlements.
Even when the love was gone, a divorce was out of the question because of mutual dependencies.
Today, however, these dependencies have been greatly reduced compared to the past, and marriages no longer have to be maintained at all costs.

Phew, where is any individuality here? Everyone is allowed to pursue their hobby or interests, after all. Why does one have to defend a purchase that is paid for by their own earnings? Just because you are married doesn’t mean you have to have the same opinion or live the same life.

This has nothing to do with lack of individuality, but with fairness and shared goals. Lack of agreements just leads to hometrainers costing 2,500€ that are not used. Just because it’s not from the money in the joint account, in my view it’s not more bearable for the partner. Gone is gone, regarding the money. Furthermore, revenge was especially emphasized... so also to be recognized by you as *irony*.

Now a new car/vacation/etc is due, which should actually be paid 50-50. Then your wife says "My account is empty because of pointless purchases and loss-making sales, I can't contribute 50%" and then? The purchase is not made? Or do you then pay, for example, 70-30?

I can answer that for you. Since I, similar to the OP, can live very(!) modestly without headaches and simply take public transport without a car, or don't place much value on traveling, I am in the comfortable position to just say: "Then not."
It has happened once, since then there are surprisingly always reserves in the savings account that is not mine. Not before.

Unless of course you never have a money shortage.

So: NOT me, no I could theoretically afford my lifestyle and even the shared apartment on my salary alone.

Or asked differently, what are you saving for? Because you have to be saving for something, otherwise the 3 accounts system would be pointless?

For nothing specific. I just have more income than expenses, savings are simply the logical consequence of that. They are currently not really necessary above a certain amount. But if they ever become necessary, they would be there.
They are not available for things I consider 100% pointless.

Exemplary. There would be fewer financial problems in some relationships if there were mutual controlling or "disciplinary measures" like these.

As you can see, something like this works

Then your wife says "My account is empty because of pointless purchases and unprofitable sales, I can't contribute 50%" and then? Is the purchase not made? Or do you then pay, for example, 70-30?
In case 1, I would be annoyed if I were you, since you wouldn't be able to go on vacation or buy a new family car

: "Then just not."

That's exactly how I see it too.
If someone can't handle money, then they have to feel the consequences. Only under pressure from suffering will the personal shortcoming be worked on