I think NCT is one of the most impactful groups of their generation music wise, probably even more than groups that are/were more popular and successful than them. NCT paved the way for the "noisy" sound many boy groups are following and adapting now (like skz), and there are more and more new groups debuting with very obvious NCT influences in their music and even MVs. And there's also the fact they're one of the most covered groups currently, who in kpop didn't cover Kick It and Boss? Even bside ballads get covered by other idols.
It's a very peculiar phenomenon considering that their music isn't exactly popular digitally.