Just a small correction, "biological gender" is usually more easily distinguished as sex. Gender would be the word applied to the internal identity. If I'm reading your indented use of the word correctly that is. When it says they don't find their gender distressing I believe it's referring to their gender identity since that's the language it sets out in the first question.

They may find distress from not being able to transition easily but that doesn't mean they are distressed from wanting to transition. It's like how someone on looking for a job may find it infuriating but they may not find having a job infuriating. Probably a bad analogy but again I'm not the wisest on the topic.

It does slightly get into transitioning not being the same and that not all go through hormone therapy or surgery but you're right, for this question it is slightly worded to imply that it is what everyone goes through.

I do agree that if it was a mental illness that wouldn't be a bad thing. I just have a major vice for correcting people on common misconceptions. Plus when it comes to labeling it a mental illness, that is often weaponised by some to say it should be seen as an issue so then the treatment is trying to "correct" the issue by changing their gender identity to match their sex. Even though when people do have gender dysphoria which may be a mental illness, the treatment is still recommended as transitioning however needed.