^As someone who was a year and half younger than my peers, I'm a big fan of skipping on occasion. The only really good year my oldest had in elementary school was the one where his 1st grade teacher arranged for him to do math with the third graders. There was no one in the gifted program (which kicked in 5th grade) that was anywhere near his math level. Once one gets to middle school or high school there are usually ways to accelerate by subject.
I wouldn't say I was wildly gifted, but I'd probably pass the bar for any gifted program. I never had a problem fitting in. My older son who was on the older side of his class I think would have been better off by skipping, but it's true it still wouldn't have been enough. The obvious thing to do was homeschooling, but he liked being with friends, so we bumbled along doing extra math at home and he complained all the time that he wasn't learning enough.