Since when do I compare Nas to Jay commercially? Jay is bigger than Nas has ever been, and he's been ahead commercially since 1999. But I, you, and everyone in rap shyt understands Jay and Nas aren't being compared commercially. They're being compared as the best MCs. Which is a far more contested debate than "who sold more albums."
You think Jay is better, I think Nas is better. End of the day for me I don't really care who you say is better. It's a subjective debate and given that both rappers have supreme resumes to even be in the conversation, why would I get mad if you choose the other guy? Hell you can add Pac and Biggie to the debate. I wouldn't bat an eye if someone said Pac is the GOAT, or Biggie is the GOAT. Those are all guys in the conversation. Wouldn't bother me any more than someone saying Martin Scorsese is the GOAT director, or Stanley Kubrick is the GOAT director. I expect those names to be in the conversation.
Who is the greatest jazz musician, is it Miles Davis or John Coltrane or Charlie Parker or Louis Armstrong? Pick one. You aren't wrong.