dexos2 is meant to deal with diesel primarily and gasoline (in countries with sometimes questionable quality fuel which contains lots of sulfur and junk). It does this at the expense of some fuel economy. Dexos 1 gen2 will be perfectly fine for gasoline engines in countries that have reliably clean fuel, like in north america. Dexos2 isn't necessarily better than dexos1 gen2 if you dont need the extra functionality of dealing with dirty fuel, though having that extra buffer might be better for those who dont mind the difference in fuel eco.
This thread has a neat little graph that is somewhat recent.
https://www.bobistheoilguy.com/forum...xos1_vs_Dexos2
btw, the importance of dexos1gen2 and/or using dexos2 over dexos 1 gen 1 or some other non-compliant oil is in supercharged/turbo applications where there was an issue with low engine load predetonation causing engine damage due to calcium based additives. The newer formulations use magnesium instead to avoid the issue.