You'd be bored after a week .Maslows hierarchy of needs would see you craving recognition,solving hunger in Africa etc in your free time
In a more enlightened society, one not prone to misusing information to persecute one another, he'd arguably be right.
It's likely much simpler: Larry thinks the solution to (his) immortality - or longevity at the very least - may be contained in Americans' collective DNA, and AI may be able to tease the answers out.
Mapping DNA is just another part of that schema.
I wish the billionaires were doing this. Instead they are hoarding wealth like angry dragons and comparing piles.