There's a huge amount of snobbery around ear piercing.
My view is, and always has been, that my DD can have them done, if she really wants (after months/years of asking to be sure), when she can look after them herself. For her, this was 10.
She went with a couple of friends at the beginning of the summer holidays and it was fab. One was cool as a cucumber, one seemed fine but then needed some sugar ten minutes later, and my DD cried for two minutes due to the shock/pain.
Took them all for ice cream afterwards and will never forget how delighted they all were. Had a few sleepovers during the holidays where they all shared tips about how they kept them clean/turned them etc. It was a shared adventure with a memory to treasure.
By the time they went into Y6 in the autumn they could take them out for PE so nothing affected there.
The snobbery by some of the other parents I know was hilarious though. "Oh I won't let x get hers done until she's 16 etc", said patronisingly.
Whatever. Judging other people's parenting decisions in this context is foolish at best.