Hominins have been around for millions of years, and for something close to two million years in parts of Eurasia. Modern humans have been around for something like a quarter of a million years, and for something close to 100,000 years in parts of Eurasia (and beyond).
What distinguishes modern humans from archaic hominins? More than anything else, the defining big picture issue has been ecological impact. Modern humans rapidly exterminated megafauna everywhere they spread (African megafauna were presumably not exterminated to the same extent because they co-evolved with modern humans giving them time to adapt to them).
Archaic hominins, in contrast, don't seem to have done more than tweak the mix of top predators in the ecosystem.
Something about the modern human lifestyle's impact on the ecological balance was crossed a tipping point that the lifestyles of Homo Erectus, the Denisovians, Homo Florensis, and the Neanderthals had not. Perhaps it was our more advanced tool kit. Perhaps it was our improved hunting tactics and strategies. Perhaps it was our greater level of group cooperation. Whatever the reason, modern humans killed far more big animals than any of our predecessors.
Our inability to stay in ecological balance with megafauna, as Neanderthals apparently did, may also have created the necessity that made a wider range of food sources a survival advantage for modern humans in a way that it was not for archaic hominins.