I remember the 1992 World Cup final. Pakistan scored 249 runs in 50 overs. England managed 227 runs in 49.2 overs. That was the normal scoring rate at the time.
Today, England smashed 234 runs in 20 overs! The hapless South Africans had to chase hard from the very first delivery. They managed 193 runs in 20 overs -- a run rate that's almost double that of the World Cup champions from 30 years ago but it still wasn't enough! Of course, the overall strategy is different because I'm comparing an ODI to a T20. Still, the contrast is quite stunning.