Yes, of course people read whole words and phrases at a time. And this makes that harder. When you systematically make many letters less easily recognizable, reading words by sight gets more painful. Sometimes just a few letters in a word are off and you can still infer it; sometimes enough letters in a word are off, and their combination/juxtaposition together with inconsistent handwriting makes it enough to have to stare at it and go "what in the world is that?".

It's remarkable what the brain is able to decipher. That's no reason to make it deliberately harder.

For writing produced quickly and expected to be read by either no one or only yourself, the combination of familiarity with your own handwriting and remembering what you wrote will make it more decipherable to you than anyone else. For anything that someone else should read, either type or optimize for legibility, please.

My reaction to seeing large amounts of calligraphy is "that's a beautiful art form". My reaction to having to read even a small amount of calligraphy, let alone quickly jotted cursive, is "can I get a transcription please?".