Boys' ones are not. So why do all girls' t shirts have to have lycra in them and be close fitting? I've had to resort to buying white T shorts and dying/customising them for DD1 and DD2, who are 9 and 11 and don't like tight fitting tops.
I also had a look at jeans in H & M - all the girls' jeans are tight fitting, all the boys' jeans came in a variety of fits, including baggy, and all had elasticated/adjustable waist, whereas the girls' ones didn't.
Why is it so impossible to buy ordinary, square cut loose fitting tees for girls?