The article mentions it later - journalists and laymen end up asking Nobel Prize winners their opinion on matters outside their area of expertise.

We don’t do that with Fields medal winners. Mainly because most people don’t even know what a Fields medal is. I can’t write a headline that relies on Elizabeth Moon’s or Stanislav Smirnov’s borrowed authority because the average joe doesn’t know who they are. But that definitely happened with multiple Nobel prize winners because the Nobel prize is that well known. A Nobel prize winners opinion on race science is inherently newsworthy.

You know how we know the Nobel is in a different league to these other awards? Because when you explain what a Fields Medal is to someone who hasn’t heard of it, you say “it’s the Nobel prize for math”.

And the fame of the prize leads to attention, which in the words of Milton Friedman, is “flattering but also corrupting”.