Almost all of the major improvements happened early on in the century, not so much in recent times. All the low hanging fruit has been picked. There is never again going to be a single technology that improves people's lives as much as mass adoption of electricity did (short of a singularity at least.) More efficient or even self driving cars compared to today's cars, will be nothing compared to what cars were for horses and trains. No single medical technology is going to have as big of an impact as antibiotics did. Cell phones are not nearly as big of an improvement as the first phones were.
Did the world really change and improve as much between 1970 and now as it did between 1930 and 1970? Did it change as much then as between 1890 and 1930?