Here in Canada at least, I was taught in elementary school to capitalize all important words (i.e. other than and, or, at, in, etc.) in a title. Is it taught differently in other places?
It's called Title Case. There are different rules depending on which style manual you're using. Some people just capitalise everything. Some people don't use it at all.
In all fairness, alternating caps is read in an extremely different way. It mimics an undulating high-low pitch that is frequently used for mockery in English. Can also be represented with a tilde, usually in a friendlier manner.
It something that always has been. Ben Franklin's Poor Richard An Almanack from 1739 uses title case. It was used in illuminated manuscripts written by monks
You're asking something that probably comes from a wide array of reasons that dates back literal centuries, even millennia.
I hate it - whoever invented title case needs their head checked. It makes it far more difficult to read.
For short titles it's fine which is probably the use to be fair, but when people on reddit/lemmy write a short essay as a 'title' man that is annoying.
In print, you can use all-caps to produce a large, attention-grabbimg headline and reduce the leading (line space) without worrying about font ascenders or descenders interfering.
Oh, my bad, I have indeed confirmed that all nouns are capitalized in German... what I meant is that I'm not sure if that's the reason why English also does it (sometimes).
See? That's what you get when you insist to write everything in lower case with weird exceptions (I is capitalized, you isn't, narcissists...) People make up even weirder exceptions. That's on you, sloppily simplistic english grammar!