This “well ackchyually“ is not particularly helpful. You’re not wrong. But this argument was lost 30 years ago. The programming field has been using “Big O” loosely.

I've had conversations at work where the difference was important. Mass adoption of quicksort implies I'm not the only one.

There's a comment thread further down that disagrees with you.

I am not interested in arguing so I'll just repeat that your article is beautiful and even though it's not entirely correct I think it has value and I appreciate the time you spent working on this and putting it out to help others.

Thank you, I appreciate that a lot.

...where?

Ah, I conflated worst case with upper bound. My mistake.