I know it is bad for the environment, I know you cannot trust it, but as an adult learning C++ in my free time, having a pseudo-human answering my questions instead of having to look at old forum posts with people often trying to prove their skills instead of giving the simplest answer ChatGPT is something I cannot just ignore — despite being a huge LLM hater. Moral of the story: none.
If it helps you feel better, it's really not that bad for the environment. Almost certainly uses less energy than searching for lots of forum posts.
If it makes you feel better, eating meat is quite bad for the environment, so if you hire a human tutor who eats meat, you're probably putting more money into funding something that damages the environment than if you use ChatGPT.
If your human tutor is vegan, drives an electric car, and never takes airplane flights, then yeah, stick with the human tutor not ChatGPT.