The issue in this thread is confusion between two separate ideas: "English is a phonetic langauge" and "English uses a phonetic script".
The former point can be debated. The latter, not. The English script is phonetic. Graphemes represent phonemes.
The English script (its writing system), which is based on the Latin alphabet (the graphic symbols) is phonetic because the symbols represent sounds and have no intrinsic semantic meaning. I think that's fairly un-debatable unless you want to make the case that emoji are part of the English script.
"t" represents a sound in the English script, a phoneme. It does not represent a thing, an idea, or anything more than an aspirated consonant sound.
There were blog posts that surfaced in the '10s trying to make a case for official inclusion of emoji into the written language. Thankfully that concept got little traction.
