I don’t think we can compare the Jesy/LM situation to the Spice Girls or One Direction, both the latter were flash in the pan type successes, one direction were together for a total of 4-5 years before they broke up. There was obvious tensions in the group and it was very clear the differences in what each of them wanted to do. They were a giant PR stunt by the label to burn hot and fast and to earn as much money as possible, they also had little control over much of what they did. You only have to look at the different paths the boys have taken since the split to see that actually they were all completely different people. Also they were on tour like 24/7, regardless of any group dynamics that is just impossible to sustain!
the Spice Girls were similar, they again only lasted about 4/5 years before the cracks showed and they split. Clear differences and tensions within the group and they also had little control over what they did. They’ve done the reunion tours and albums but they’re mostly just to keep the bank accounts topped up.
Little Mix have been together for 10 years now, although there’s obviously been some differences with Jesy, the bond the girls have is visible and after leaving their old label they’ve clearly gained a lot of control over the band now. They seem to have a lot in common and are pretty cohesive as a group.
They also aren’t just album machines churning one out every year for the cash dolla like 1D were, they take breaks and look after themselves. I can see them going for a while longer yet! (At least I hope so!)