They would tell you he's the best basketball player ever.
As for best QB, it's easy to have a class of top 3 to 5 best QBs of all-time-- Brady is obviously in the top 3 but arguments can be made for any one of them. It's like the top 5 MC discussion in rap music. Inherently subjective.
True GOATs stand out past their peers though. I hate Michael Jordan with every fibre of my soul, and I do think it can be argued that there is a player in NBA history that is "better", but when you factor his career, on-court productions, off-court impact, and how the league (and pop-culture) changed after him? He's the greatest. Basketball was never the same after him. Just like boxing was different before and after Ali.
To be the greatest necessitates the whole package. How do you supersede your on-court contributions? Severing social context from professional athletes is dumb, especially seeing as (generally) there's no objective way to use stats to bolster a unanimous agreement. Is the best PG the one who has the most assists? Or the one who started on the most championship teams? Is the best QB the one with the best passing stats? Or the one who won the most? How much does it matter having 5 rings than 4? Are Jordan's 6 more impressive than Kareem's scoring record?
It's all messy. Thwacks of boxers have stats that on first glance are more impressive than Ali's-- so why is he considered the unanimous GOAT?