I think this would be a pretty cool thing, that if you get enough fame stars in a category you can build a huge monument, like if you get enough scientist stars you can build a World's Fair, if you get enough asthete stars you can build a statue of your avatar, enough militarist stars and you can build a huge triumphal arch and so on. These monuments would or would not give any gameplay advantages but maybe more be a thing that showcase huge achievement in a specific area, aka getting alot of fame stars in that area.