I have actually thought about this situation.
However, I prefer devising new characters. I hate those extra symbols. Think of a keyboard. You might as well make new characters as add keys for all the different “accents” on extant letters.
We have a wonderful flexible language, but the “diversity” that ultimately molded it is also what causes all the confusion. Far too many influences that contradict each other.
Our current set of characters are actually simplified forms of what used to be pictographs. Biggest example is “A”, derived ultimately from Phoenician “aleph”, which means an ox; the current form of the capital letter is actually upside down so you can’t really see the horns of the ox until you turn it 180 degrees.