A major issue with trying to write English phonetically is that pronunciation is not constant or consistent. Not only does it change regionally, and over time (accents change with each generation), but also by placement within a phrase (weak forms and strong forms).
Even something as simple as the short "a" in cat varies dramatically in sound depending on where you hear it spoken.
Phonetics can be really complicated.
Bobby Finn English class day 13
ItsBobbyFinn
And this is only the lesson 13.

There are 12 more on his channel.