Doctors disagree as I have already shown. And how is it barbaric? It doesn't hurt the child (when done properly in a medical facility, not at home with a Rabbi), it only helps the child.
These are the functions of the foreskin.
Functions:
to cover and bond with the synechia so as to permit the development of the mucosal surface of the glans and inner foreskin.
to protect the glans penis from friction and abrasion throughout life.
to keep the glans moisturized and soft with emollient oils.
to lubricate the glans.
to coat the glans with a waxy protective substance.
to provide sufficient skin to cover an erection by unfolding.
to provide an aid to masturbation and foreplay.
to serve as an aid to penetration.
to reduce friction and chafing during intercourse.
to serve as erogenous tissue because of its rich supply of erogenous receptors.
to contact and stimulate the G-spot of the female partner
The foreskin/glans combination produce a powerful anti mmicrobial compound called Langerin that keeps the area clean and disease free
Provides a lubricating function that assists in sexual intercourse.
Damages besides the loss of the prior functions:
Neural and vascular damage to the penis.
50-75% loss of sexual sensitivity.
Less intense orgasms
removes 75% of the sexually sensitive tissue on your penis
By the time you individual reaches their late 30's and early 40's the glans becomes dried out and calloused over with scar tissue from rubbing on clothes and other material the individuals entire life.
Can cause inability to ejaculate( extremely rare)
Lubrication
There is more, but I'm a bit rusty on those at the moment and will list them later if need be.