Funnily, I did a lesson for my fourth graders today on almost exactly this point. Written conventions are there in large part to make written language mimic spoken language. Most of the time, you don’t want people to pay attention to your specific choices about conventions. (Most of the time, you’re not e.e. cummings).
win sumthng iz mispeld, u kan red it, butt it taxe mor bran powr to red it.
The brain power that’s spent deciphering the unconventional spelling draws attention to the spelling itself, creating a double-whammy: instead of paying attention to the content of your writing, to its concepts, the reader ends up spending effort deciphering the writing, and then spends more effort thinking about why you made those unconventional decisions.
With my fourth graders, I was just desperately hoping to persuade them that they should follow written conventions even when they didn’t understand why it was important. With grown-ass adults, I end up feeling a little irked when they waste my brain-power on stubbornly idiosyncratic spelling decisions like “enuf.” It makes me (and most other fluent readers) slightly less able to focus on their points, and in doing so comes across as rude in much the same way that it’d be rude during a conversation to be snot-snorting.