You teach Russian or Spanish with phonics. You teach Chinese with whole-word. English needs a bit of both, since it is mostly phonetic. An on-demand approach to phonics works very well. The rules and exceptions are pointed out as mistakes are made. This avoids the boredom of drilling endless phonics rules and the long-term difficulty of whole-word. A common mistake with phonics is the accidental association of specif…
The pin-pen merger is a reality for millions of people all over the country, and we are understanding each other and everyone else just fine.
Check the map: https://www.ling.upenn.edu/phono_atlas/maps/Map3.html
Also, as a person who actually had years of speech therapy despite a very early mastery of reading, it's honestly a bit offensive to see you conflating the two subjects here. Mutual misunderstandings while reading between two people who each speak different dialects is not a form of speech pathology. Teaching someone else your dialect through reading with them does not correct genuine speech pathology either.