Excuse of major shirk in akhirah

So I'm asking this just to get clarified. If one is land where Quran and Sunnah is available, we know he is a mushrik, but does he 100% go to hellfire? Or is it left to Allah and they may be like Ahlul Fatra even if the Quran and Sunnah is accessible. In other posts I have seen scholars stating grave worshippers their deeds are not accepted and jannah is forbidden for them. Does this also apply to kuffar, and to go more specific, if one is fed up with only Islamophobic or Salafophobic tuff would this be an excuse? Or is it all left to Allah azza wa jal. Sorry for asking a little weird JazakAllahu Khairan.