@StillCoughingandLaughing I see the logic, but had just never seen it written as one word, in any context, until a few years ago, which is why I wondered if it was an American usage that had started to become more widespread.
For the record, I have never liked 'alright' and always write 'all right', but I’m sure I remember being told as a child that 'alright' was equally (or maybe more?) correct. I came across it written that way a few days ago, and it pulled me up short because I realised I hadn't seen it for a very long time. It mostly appears in older books and now seems to be almost obsolete which is 'alright' with me!
However the argument about the different meanings does suggest why it originally existed: 'Well done, you got them all right' isn't the same as 'I managed it alright'. But people clearly don't like how 'alright' looks and so over time, we have replaced it with 'all right'.
Which is probably sad news for those who don't like linguistic change and object to the use of 'alot' etc, because if enough people use an 'incorrect' term for long enough, eventually it gets promoted to 'both variants are acceptable' and ultimately it may supplant the 'correct' usage. See also 'any more' / 'anymore' which I think is a case of people seeing 'anyway' 'anyhow' etc and assuming, by extension, that 'any more' used adverbially for time, must be one word, like 'sometimes' or 'forever', which presumably originated as two-word phrases.
Interestingly, my autocorrect has just offered me 'forevermore' as a single word. I think if I ever had cause to use that expression (although why would you?), I would have serious pause over whether that was one word or two (forever more - does that look wrong?). But then I always cringe about writing 'nevertheless' which I know is correct but looks utterly ridiculous IMO. If that can be a word, then really there's no reason why 'alot' shouldn't be one.
It would be helpful (especially to language learners) if there was some consistency about whether adverbial expressions were always one word or always separate words, but like everything else in English, of course it's completely random! 