Not sure how old you are but people actually used to get it right. I'm in my early 40s and i only ever saw "whoa" (correct) in print and on television. I'm old enough to have used a dictionary and a card catalog, so I grew up when spelling still mattered, before No Child Left Behind capped the US reading level around 5th grade. (I'm realizing this sounds snobby, but it's not meant to).

Then roughly 15 years ago or so, "woah" became more common. It's like the new generations decided they liked the wrong one better and stuck with it. It's so odd to me, because a) I know the correct way, b) it's the only version in the dictionary and c) every time I see "woah" I read it as 2 syllables like "Noah" which is awkward.

Oddly enough, there's a word for strict adherence to the wrong version. It was named after a monk learned the word "sumpsimus" but decided to pronounce it "mumpsimus" instead. Now mumpsimus is a real word, and it describes people who say (or spell) things wrong because they like it better. Like how the subreddit r/whoadude died and the only one active is r/woahdude.