That's a good point, but most boys have a hernia check and a medical at school around age 11-12 in the UK. I would think that a buried penis is something that could be eyeballed and referred for further management, but still wouldn't require a doctor or nurse to measure a young chaps old chap, so to speak.
We had hernia checks as well yet still nothing was noted. The problem is that boys are so variable during puberty. I started early and became my full size at about 13 yet I had friends my same age who didn't start puberty until 17. There is no way for a doctor to be certain where a boy is in puberty without using an orchidometer to measure testicular volume as that's the only reliable way to measure pubertal development, yet very few pediatricians even have one.
Rather than measure the penis, I'd suggest a doctor ask the boy to press down on his fat pad, measure the testicular volume, and then palpate the area. There is no need to measure penis size (to my admittedly unprofessional knowledge). Mine certainly wasn't. Flaccid erect length stretching can be observed, if necessary, by asking the patient just to pull it forward.
There is a difference between medical and prurient interests yet there is no reason we should neglect the sexual health of males. Genital examinations should be regular in males of all ages as they are with women. Heaven knows men have plenty of possible problems, some serious even when young. I've run into a few young men here who are still in their teens but have numbness in their penis, inability to maintain erection, lesions on the penis, phimosis, chordee, tight frenulums, etc. etc. Just look through the content of this sub-forum! Most of these men would rather check the internet because of their uncertainty and embarassment yet I don't know a woman who wouldn't immediately schedule an appointment with a gynecologist with analagous problems. I think the reason for this is because doctors, at least here in the US, are terribly circumspect about examining male genitalia. Look on YouTube and you can find a number of videos about giving a thorough, complete physical on an adult male and the whole process runs about half an hour. How do you do that if you see 35 patients a day? I haven't dropped my pants for a GP except for a cyst on my butt in over 20 years! I think that's a bad reflection on the medical profession as a whole because it says that male genital health takes a backseat to female genital health and that's reflected in our society. A few simple tests and questions are all a doctor needs to know that a male's genitals are functioning as they should be.