Clear, effective communication is best when there are no, or at least very few, grammatical errors to distract the reader, and in the cases given above, and more, spell-checkers don't help.
That only matters to you because you were taught different spellings for those words.
Consider the word 'read'; it's pronounced like 'reed' when used in the present tense, and like 'red' when used in the past tense, but spelled the same in either case. Does that disrupt your 'flow'? I'm willing to bet it doesn't, because you were taught the same spelling for both those words (and they are different words!)
Now consider the word 'about'. It can mean 'almost', as in "I'm about to arrive", or it can me 'regarding', as in "This book is about...". If you were taught the 'regarding' definition of 'about' is spelled 'abowt', I'm sure you would have added 'about/abowt' next to 'to/too/two' as something that disrupts your flow when misused.
Are you going to claim that the difference is no longer relevant? If so, I'm going to disagree, but recognise that there's no point in debating the issue. Language mutates over time, differences become irrelevant, other differences and distinctions emerge. Even so, using newer forms can significantly impede understanding.
If that's not your point then I'm not sure what you're trying to say. Let me say it differently.
The comment to which I was replying said:
> ... both spelling and character recall can be delegated to technology ... I use spelling checkers ...
My point is that spelling checkers don't help in the cases I sight. Sorry, cite. If someone uses "you're" when they mean "your" then it disrupts my flow when I'm reading and impairs effective communication, and likely I'm not the only one.
So using a spelling checker is useful, and indeed, I use one, but they do not solve all the problems.
You are correct that "read" being pronounced in different ways according to the context does not disrupt my flow in the same way, but that observation does not diminish my point that spelling checkers do help in all cases.
e.g. 'about his person' (carrying something with you) 'he is about' (he is close / near) 'he is out and about' (he is some distance away)
etc.
"I'm about to arrive" -> "I'm close to arrival but not here right now".
"This book is about..." -> "This book is roughly this short approximation, because I can't fit the entire synopsis in a sentence,..."
"About his person" -> "Close to him, possibly so close as to be carrying it"
"He is about" -> "He is somewhere around here, but not in this exact spot"
"He is out and about" -> "He is out somewhere in this area"
"Gone walkabout" -> "Traveling with no specific destination"
"Roundabout" -> "Traffic control method that encourages vehicles to take a more circuitous passage, rather than directly crossing an intersection"
The context of the word changes the interpretation, but the essential function of "about" is the same in each case.
I doubt spelling is a competitive sport in saner languages, though I imagine that character writing (and reading) contests could be a thing in languages with large numbers of written characters.
Like long division, both spelling and character recall can be delegated to technology, but I'm not sure what I think of this as a general principle. I use spelling checkers and I like phonetic character input methods, but I dislike grammar checkers.