Why is the pH scale always thought of as 0-14?

So I have biology class right now and my professor was talking about a lake that had a pH of -7. And then it hit me that I’ve always known pH to be 0–14. Mainly because thats always what I’ve seen and been taught in school. Now thinking about it, it makes sense pH wouldn’t be confined to those numbers as its a negative logarithmic scale of dissolved hydronium ions, so why couldn’t a substance have a very high concentration of them? Fluoroantimonic acid has a pH of -25 (i could only imagine what that would do if spilled on something lol)

So the question is, if these super low pH’s are possible, why are we always taught the 0–14 scale?