In my gym, the training path for JO and elite is different.
The kids training elite have extra hours during the afternoon, although they usually also practice with JO in the evening. We don't really actively recruit numbers for the elite training group - it's just if there's a young kid who's picking up skills like crazy in JO, they get directed to it. A lot of times it doesn't work out and they wind up back in the regular JO program after a year. And the focus isn't on succeeding in JO competitions - some of the kids who have trained elite don't compete a full season every year, in order to focus on preparing for camp and testing. So the pre-elites might only compete L10 for a few meets.
Whereas the gymnasts who compete all the way through to L10 maybe were training pre-elite at some point, but decided it wasn't for them (or their parents did), or something set them back. Or maybe they were older than the usual age for pre-elite, or didn't demonstrate that ability to pick up skills like crazy. Or they excel at some events, but don't have the across-the-board ability that elites need.