[MattHood0]

Music teacher with degree here, the Stack Overflow answers are correct as far as modern usage goes, with respect to common-practise tonal harmony at the very least. Your second reason is just an alternative way of phrasing all of the answers that cite F major as an example. Yes, in non-equal temperaments they can be different pitches, but I highly doubt that someone asking the difference between sharps and flats is concerned with niche subsets of early music and contemporary classical.

[seertaak]

Thanks for your contribution -- I must admit I'm not a teacher, and my degree is in another subject. I also acknowledge that the second part of my answer is a weasel exit clause which uses the same reasoning as the stackoverflow answers ;)

> but I highly doubt that someone asking the difference between sharps and flats is concerned with niche subsets of early music and contemporary classical

Well, the OP's question has the sentence: "If we can get away with just having sharps (aka black notes on a piano) then why complicate things and add flats as well?"

To my mind, this means the OP understands the idea of enharmonic equivalents, and wants to know why it wasn't simply decreed that, e.g., "sharps it shall be". To give an analogy from mathematics, it doesn't matter whether we add 0.5 to 1 or subtract 0.5 from 2, we still call it 1.5, not "two minus point 5" or "one and point five". (Notwithstanding those crazy French and Germans!)

So I'm curious, given your background, what your response to this latter question would be. Or to phrase it differently: if music notation were invented in 2018, would it look substantially the same?