Afaik, it did not worked like that. Repeating grades did not lead to better success, which was one reason for ending it. The age difference between failed kid and younger kids in next class did not made anything easier either.

And kids at the very bottom have better and more support available now. It is not perfect, it often sux and is not available to everybody. I definitely don't mean to say it is somehow super great. But the kids at the bottom with cognitively issues or impulsive control issues have better chance to learn more then used to be normal.

When I was growing up you were bumped up still (to stay with age group), but you took basic courses until you were back up to speed, then you were moved to standard, then advanced, then AP. I sucked at AP, but standard / advanced were good. The AP kids must have studied so hard - I bombed those classes when I tried them.

But that also was seen as discriminatory I think because it wasn't that easy to move out of basic etc once you were there so I think they stopped this as well - I think system was called tracking.

I'm not sure how bumping them up a grade is any better. It's that not just a massive waste of time for everyone involved?

My take on it is they basically give up on them and get them out of the system faster that way.

If the kids failed either way, it's cheaper to make them fail in 12 years than 13 or 14.