Many people in first world countries will. Some people in first world countries and probably most in Indian villages don't even have 4g yet. So I doubt that in 1000 days they will have 5g when we are barely producing any devices today with that capability.
The reason they don't have 4g now is mostly because there's no 4g service, not because people can't afford 4g enabled phones. I'm pretty sure by now 4g phones are just as cheap as 3g phones.