The people born in 10 years will have access to a hard money that is time proven, more stable and less risky than it was 10 years ago. They will also see the price of their bitcoin go up relative to fiat. The same goes for people born in 300 years time.
Regarding developing countries, bitcoin provides anyone with a phone access to a bank, and one that offers better savings accounts than any fiat account.
Go and study it for 100hrs and if you combine that with a bit of intelligence, you'll be in the same position as the "lucky" bitcoiners who get wealthy buying it earlier.
Alternatively wait until every man and his dog already have it and the price has stabilised and it's a no brainer (say 10 or 20 years)
Regarding developing countries, bitcoin provides anyone with a phone access to a bank, and one that offers better savings accounts than any fiat account.