We don't eat salted butter or margarine in Europe. And we're still just fine. You're just used to salt so you can't imagine not having it. It's the same with sugar in tea. It's hard to stop putting it in, but once you're over the adjustment period, you don't feel like you want to go back. Sweetened drinks in general just taste like sugar to me now. I suppose they same might be true for oversalted food.

100% agree. Stop eating Maruchan ramen, ask for no salt on your fries. There’s lots of ways to reduce salt. Unsalted butter/margarine on your food has got to the stupidest way to cut down on your salt intake.

Salt is contained in a lot of products. Got salted butter? Smear it on bread. Guess which ingredient is used in bread. Correct: salt. Maybe you put some cold cuts on it. They've got a lot of salt. What about cheese? Salt again. Now you move on to your coffee. You put dairy milk in it: salt. Lunch? Probably a lot of salt. Dinner? Needless to say. If you snack some chips, well, obviously it's a shitload of salt.

Salt is everywhere. Especially in today's food industry. Having salt is not necessarily bad for one's health – in fact, we do need salt for our body to function – but as usual it's the amount that matters.

And according to several dietary authorities worldwide, most people eat too much salt.

WHO:

The global mean intake of adults is 4310 mg/day sodium (equivalent to 10.78 g/day salt) (1). This is more than double the World Health Organization recommendation for adults of less than 2000 mg/day sodium (equivalent to < 5 g/day salt).
https://www.who.int/news-room/fact-sheets/detail/salt-reduction

FDA (USA):

Americans consume on average 3,400 milligrams (mg) of sodium per day—nearly 50%more than the 2,300 mg limit recommended by federal guidelines for people 14 years and older. Recommended limits for children 13 and younger are even lower.
https://www.fda.gov/food/food-labeling-nutrition/sodium-reduction

Overview in EU:

International health-related organisations have issued recommendations to limit salt intake to no more than 5 or 6 g per day (see Table 3A). In the EU, most national recommendations that quantify salt intake recommend the same. [...]
In the majority of European countries, the range of intake is 7 to 12 grams of salt per day
https://knowledge4policy.ec.europa.eu/health-promotion-knowledge-gateway/dietary-saltsodium_en

Salt is one of those substances which have large effects even in low doses. Therefore, being above the recommended intake on average increases risks of suffering mainly from:

cardiovascular diseases, stomach cancer and chronic kidney disease
https://knowledge4policy.ec.europa.eu/health-promotion-knowledge-gateway/dietary-saltsodium_en

So, if you're interested in your health, try to get an overview on how much salt you consume on average. And if it's above the recommended intake (which is usually the case), consider whether you really really can not live without salted butter or try to cut down on salt with other meals. And probably, taking the shaker off the table won't be enough.