Last year's playoffs? When he had Kyrie Irving (a player about as good as Lillard) and Kevin Love?
How many championships did he win that year?
I don't actually think James is borderline--I do think judging talent by wins is supremely flawed. Especially since we see constant evidence that players labeled "good stats on bad teams" suddenly have success when they get some good teammates. Michael Jordan was labeled as a "stats guy" who couldn't compare to Magic and Bird--until he actually got a talented team around him. Same for Kevin Garnett and LeBron James.
It's also weird that you would label Curry "borderline" since when he won the title in 2015, he didn't have a "bunch of All Stars" around him. He had one, in Klay Thompson, and no one would call Thompson a superstar.