Nominal GDP growth and real GDP growth are very different things, and it's the latter people are referring to. If it was only nominal that mattered, we could have a arbitrary economic growth through inflation.
Several generations ago, some of my ancestors (my great grandparents) came here and bought their farmland for $10. Now I can barely buy a beer for 10 dollars. Yet we don't measure GDP in 1900 dollars, or in year 3000BC shekels.
Regardless, in many ways, my beer today IS worth more than a farm in 1900. My beer was made because of generations of farmers growing grain, building up their homesteads, brewers buying equipment and employed generations of employees, farming equipment improving efficiency, and everything else that goes into the supply chain. Simply put, the value of technological progress is built into current price levels.