I have two boys, and when they were of school age it was never an issue. I never had to have trousers tailored to fit them.
Which is great. I've never had a problem getting trousers to fit me as a woman. But as many posters pointed out just because it isn't a problem for you doesn't mean it isn't a problem for others.
My son was very tall but very slim so buying long enough trousers meant they were way to big around the waist. Other boys we knew who were larger in the waist had to buy larger trousers which were far too long. This is when they were buying boys trousers that come in ages rather than mens trousers that have a separate waist and length.
Clingy or 'revealing' clothing emphasises the sexed body. Looser fitting garments do not
And? Is that not up to the wearer of said clingy or revealing garment to decide?
it is only masculine codes which prevent them from doing so,
That wasn't the discussion. The discussion was would women and girls be uncomfortable around boys and men wearing short skirts. A poster said that there's no problem with them wearing longer length skirts, which shouldn't be the case should it? If women and girls can wear short skirts then men and boys should be able to wear the same.
So, what you are saying that is that girls should be free to choose either trousers or skirts, and that boys should also be free to choose trousers or skirts; or maybe shorts - as a compromise measure between what is realistic and what is ideal?
I think girls should have the choice of skirts or trousers and boys should have the choice of shorts or trousers as a compromise between what is realistic and what is ideal.