This author writes in ESL better than 99% of the people I've worked with in an English-native country, including myself. It's fascinating to read just how much more emphasis good-quality written English seems to have in Kenya than it does here in Australia (at least in the public education system where I have experience). I suppose that it's understandable, given that it gates access to higher-level education opportunities.
I don't really understand the aversion some people have to the use of LLMs to generate or refine written communication. It seems trigger the "that's cheating!" outrage impulse.