It is not about confusion, it is about convenience. I like the idea that water boils at 100°C since it is maybe the most important temperature in cooking. I like the fact that I can measure 500mL of water on a scale as 500g (and other liquids with a small error). Small details that make it more convenient in metric.

But there is something else, and I am asking you the question. Since you and your wife live in countries with different unit systems, isn't problem when doing each others recipes?

I mean I live in Europe, and if the recipe calls for 4 ounces of butter, I don't have a 4 ounces stick of butter, I have a 125g stick, which is not exactly that. A quart of milk is not exactly the liter I have. And my oven doesn't do 350°F, it does 180°C which is not exactly the same. In the end, I will have to adjust the recipe to my standards, and things may be lost (or gained) in translation, but it won't be the same.

For what it's worth, if looking for an English recipe I just add "UK" to my search to avoid American measurements. I find British recipes are also less likely to require some processed American ingredient unavailable in the EU. ("Add the miracle whip," what?)