Certainly, an economy can produce more widgets if you’re a lean, mean, automated machine… as opposed to a blacksmith with a hammer and forge.
But there are other factors as well. Population growth. Accounting standards. And of course, the continued inflation of the currency. $1 today buys a whole lot less today than it did a century ago, so when comparing, it’s important to find a better standard of measurement.
There are a number of pricing yardsticks we could use… like the cost of a New York City cinema ticket (25 cents in 1935, $20 today). But it would be awkard to calculate GDP in terms of billions of cinema tickets.